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fetchmail(1)		  fetchmail reference manual		  fetchmail(1)

NAME
       fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server

SYNOPSIS
       fetchmail [option...] [mailserver...]
       fetchmailconf

DESCRIPTION
       fetchmail  is  a mail-retrieval and forwarding utility; it fetches mail
       from  remote  mailservers  and  forwards	 it  to	 your  local  (client)
       machine's  delivery  system.   You  can	then handle the retrieved mail
       using normal mail user agents such as mutt(1), elm(1) or Mail(1).   The
       fetchmail utility can be run in a daemon mode to repeatedly poll one or
       more systems at a specified interval.

       The fetchmail program can gather mail from servers  supporting  any  of
       the  common  mail-retrieval protocols: POP2 (legacy, to be removed from
       future release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.  It can also use
       the ESMTP ETRN extension and ODMR.  (The RFCs describing all these pro‐
       tocols are listed at the end of this manual page.)

       While fetchmail is primarily intended to be used over on-demand	TCP/IP
       links  (such  as	 SLIP  or PPP connections), it may also be useful as a
       message transfer agent for sites which refuse for security  reasons  to
       permit (sender-initiated) SMTP transactions with sendmail.

       If fetchmail is used with a POP or an IMAP server, it has two fundamen‐
       tal modes of operation for each user account from  which	 it  retrieves
       mail:  singledrop-  and	multidrop-mode.	 In singledrop-mode, fetchmail
       assumes that all messages in the user's account are intended for a sin‐
       gle  recipient.	 An  individual mail message will not be inspected for
       recipient information, rather,  the  identity  of  the  recipient  will
       either default to the local user currently executing fetchmail, or else
       will need to be explicitly specified in the configuration  file.	  Sin‐
       gledrop-mode  is	 used  when  the fetchmailrc configuration contains at
       most a single local user specification for a given server account.

       With multidrop-mode, fetchmail is not able to assume that there is only
       a  single  recipient,  but rather that the mail server account actually
       contains mail intended for any number of different recipients.	There‐
       fore,  fetchmail must attempt to deduce the proper "envelope recipient"
       from the mail headers of each message.	In  this  mode	of  operation,
       fetchmail almost resembles an MTA, however it is important to note that
       neither the POP nor IMAP protocols were intended for use in this	 fash‐
       ion,  and  hence	 envelope information is often not directly available.
       Instead, fetchmail must resort to a process of informed	guess-work  in
       an attempt to discover the true envelope recipient of a message, unless
       the ISP stores the envelope information in some header  (not  all  do).
       Even  if this information is present in the headers, the process can be
       error-prone and is dependent upon the specific  mail  server  used  for
       mail  retrieval.	  Multidrop-mode is used when more than one local user
       is specified for a particular server account in the configuration file.
       Note  that  the	forgoing discussion of singledrop- and multidrop-modes
       does not apply to the ESMTP ETRN or ODMR retrieval methods, since  they
       are  based upon the SMTP protocol which specifically provides the enve‐
       lope recipient to fetchmail.

       As each message is retrieved, fetchmail normally delivers it  via  SMTP
       to  port 25 on the machine it is running on (localhost), just as though
       it were being passed in over a normal TCP/IP link.  fetchmail  provides
       the  SMTP  server  with	an  envelope  recipient	 derived in the manner
       described previously.  The mail will then be delivered locally via your
       system's	 MDA (Mail Delivery Agent, usually sendmail(8) but your system
       may use a different one such as smail, mmdf, exim, postfix, or  qmail).
       All  the	 delivery-control mechanisms (such as .forward files) normally
       available through your system MDA and local delivery agents will there‐
       fore work automatically.

       If  no  port 25 listener is available, but your fetchmail configuration
       was told about a reliable local MDA, it will use	 that  MDA  for	 local
       delivery instead.

       If  the	program fetchmailconf is available, it will assist you in set‐
       ting up and editing a fetchmailrc configuration.	 It runs under	the  X
       window  system and requires that the language Python and the Tk toolkit
       be present on your system.  If you are first setting up	fetchmail  for
       single-user  mode,  it is recommended that you use Novice mode.	Expert
       mode provides complete control of  fetchmail  configuration,  including
       the  multidrop  features.   In either case, the 'Autoprobe' button will
       tell you the most capable protocol a  given  mailserver	supports,  and
       warn you of potential problems with that server.

GENERAL OPERATION
       The  behavior  of fetchmail is controlled by command-line options and a
       run control file, ~/.fetchmailrc, the syntax of which we describe in  a
       later  section  (this  file  is	what the fetchmailconf program edits).
       Command-line options override ~/.fetchmailrc declarations.

       Each server name that you specify following the options on the  command
       line  will be queried.  If you don't specify any servers on the command
       line, each 'poll' entry in your ~/.fetchmailrc file will be queried.

       To facilitate the use of fetchmail in scripts and pipelines, it returns
       an appropriate exit code upon termination -- see EXIT CODES below.

       The  following  options modify the behavior of fetchmail.  It is seldom
       necessary to specify any of these once you have a working  .fetchmailrc
       file set up.

       Almost  all  options  have a corresponding keyword which can be used to
       declare them in a .fetchmailrc file.

       Some special options are not covered here, but are  documented  instead
       in sections on AUTHENTICATION and DAEMON MODE which follow.

   General Options
       -V | --version
	      Displays the version information for your copy of fetchmail.  No
	      mail fetch is performed.	Instead, for  each  server  specified,
	      all  the	option information that would be computed if fetchmail
	      were connecting to that server is displayed.  Any non-printables
	      in  passwords  or other string names are shown as backslashed C-
	      like escape sequences.  This option is useful for verifying that
	      your options are set the way you want them.

       -c | --check
	      Return  a status code to indicate whether there is mail waiting,
	      without actually fetching	 or  deleting  mail  (see  EXIT	 CODES
	      below).  This option turns off daemon mode (in which it would be
	      useless).	 It doesn't play well with queries to multiple	sites,
	      and doesn't work with ETRN or ODMR.  It will return a false pos‐
	      itive if you leave read but undeleted mail in your server	 mail‐
	      box  and	your  fetch protocol can't tell kept messages from new
	      ones.  This means it will work with IMAP, not  work  with	 POP2,
	      and may occasionally flake out under POP3.

       -s | --silent
	      Silent  mode.   Suppresses all progress/status messages that are
	      normally echoed to standard output during a fetch (but does  not
	      suppress actual error messages).	The --verbose option overrides
	      this.

       -v | --verbose
	      Verbose mode.  All control messages passed between fetchmail and
	      the  mailserver are echoed to stdout.  Overrides --silent.  Dou‐
	      bling this option (-v -v) causes extra diagnostic information to
	      be printed.

   Disposal Options
       -a | --all | (since v6.3.3) --fetchall
	      (Keyword: fetchall, since v3.0) Retrieve both old (seen) and new
	      messages from the mailserver.  The default is to fetch only mes‐
	      sages  the  server has not marked seen.  Under POP3, this option
	      also forces the use of RETR rather than  TOP.   Note  that  POP2
	      retrieval	 behaves  as  though --all is always on (see RETRIEVAL
	      FAILURE MODES below) and this option does not work with ETRN  or
	      ODMR.   While  the -a and --all command-line and fetchall rcfile
	      options have been supported for a long time, the --fetchall com‐
	      mand-line option was added in v6.3.3.

       -k | --keep
	      (Keyword:	  keep)	  Keep	 retrieved   messages  on  the	remote
	      mailserver.  Normally, messages are deleted from the  folder  on
	      the  mailserver  after they have been retrieved.	Specifying the
	      keep option causes retrieved messages to remain in  your	folder
	      on the mailserver.  This option does not work with ETRN or ODMR.
	      If used with POP3, it is recommended to also specify the	--uidl
	      option or uidl keyword.

       -K | --nokeep
	      (Keyword:	 nokeep)  Delete  retrieved  messages  from the remote
	      mailserver.  This option forces retrieved mail  to  be  deleted.
	      It may be useful if you have specified a default of keep in your
	      .fetchmailrc.  This option is forced on with ETRN and ODMR.

       -F | --flush
	      POP3/IMAP only.  This is a dangerous option and can  cause  mail
	      loss  when  used improperly. It deletes old (seen) messages from
	      the mailserver before retrieving new  messages.	Warning:  This
	      can  cause  mail	loss if you check your mail with other clients
	      than fetchmail, and cause fetchmail to delete a message  it  had
	      never  fetched  before.  It can also cause mail loss if the mail
	      server marks the message seen after retrieval  (IMAP2  servers).
	      You  should  probably  not use this option in your configuration
	      file. If you use it with POP3, you must use the  'uidl'  option.
	      What  you	 probably  want	 is  the default setting: if you don't
	      specify '-k', then fetchmail will automatically delete  messages
	      after successful delivery.

       --limitflush
	      POP3/IMAP	 only, since version 6.3.0.  Delete oversized messages
	      from the mailserver before retrieving  new  messages.  The  size
	      limit  should  be	 separately specified with the --limit option.
	      This option does not work with ETRN or ODMR.

   Protocol and Query Options
       -p <proto> | --proto <proto> | --protocol <proto>
	      (Keyword: proto[col]) Specify the protocol to use when  communi‐
	      cating with the remote mailserver.  If no protocol is specified,
	      the default is AUTO.  proto may be one of the following:

	      AUTO   Tries IMAP, POP3, and POP2 (skipping  any	of  these  for
		     which support has not been compiled in).

	      POP2   Post Office Protocol 2 (legacy, to be removed from future
		     release)

	      POP3   Post Office Protocol 3

	      APOP   Use POP3 with old-fashioned MD5-challenge authentication.
		     Considered not resistant to man-in-the-middle attacks.

	      RPOP   Use POP3 with RPOP authentication.

	      KPOP   Use POP3 with Kerberos V4 authentication on port 1109.

	      SDPS   Use POP3 with Demon Internet's SDPS extensions.

	      IMAP   IMAP2bis,	IMAP4,	or  IMAP4rev1 (fetchmail automatically
		     detects their capabilities).

	      ETRN   Use the ESMTP ETRN option.

	      ODMR   Use the the On-Demand Mail Relay ESMTP profile.

       All these alternatives work in basically the  same  way	(communicating
       with standard server daemons to fetch mail already delivered to a mail‐
       box on the server) except ETRN and ODMR.	 The ETRN mode allows  you  to
       ask  a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
       higher) to immediately open a sender-SMTP  connection  to  your	client
       machine and begin forwarding any items addressed to your client machine
       in the server's queue of undelivered mail.   The ODMR mode requires  an
       ODMR-capable  server  and  works similarly to ETRN, except that it does
       not require the client machine to have a static DNS.

       -U | --uidl
	      (Keyword: uidl) Force  UIDL  use	(effective  only  with	POP3).
	      Force client-side tracking of 'newness' of messages (UIDL stands
	      for "unique ID listing" and is described in RFC1939).  Use  with
	      'keep'  to  use  a  mailbox  as  a baby news drop for a group of
	      users. The fact that seen messages are skipped is logged, unless
	      error  logging  is  done	through syslog while running in daemon
	      mode.  Note that fetchmail may automatically enable this	option
	      depending	 on upstream server capabilities.  Note also that this
	      option may be removed and forced enabled in a  future  fetchmail
	      version. See also: --idfile.

       --idle (since 6.3.3)
	      (Keyword:	 idle,	since before 6.0.0) Enable IDLE use (effective
	      only with IMAP). Note that this works with only one folder at  a
	      given  time.   While  the idle rcfile keyword had been supported
	      for a long time, the --idle command-line	option	was  added  in
	      version  6.3.3.  IDLE  use  means	 that fetchmail tells the IMAP
	      server to send notice of new messages, so they can be  retrieved
	      sooner than would be possible with regular polls.

       -P <portnumber> | --service <servicename>
	      (Keyword: service) Since version 6.3.0.  The service option per‐
	      mits you to specify a service name to connect to.	 You can spec‐
	      ify  a decimal port number here, if your services database lacks
	      the required service-port assignments. See the FAQ item R12  and
	      the  --ssl  documentation	 for  details. This replaces the older
	      --port option.

       --port <portnumber>
	      (Keyword: port) Obsolete version of --service that does not take
	      service  names.	Note: this option may be removed from a future
	      version.

       --principal <principal>
	      (Keyword: principal) The principal option permits you to specify
	      a service principal for mutual authentication.  This is applica‐
	      ble to POP3 or IMAP with Kerberos authentication.

       -t <seconds> | --timeout <seconds>
	      (Keyword: timeout) The  timeout  option  allows  you  to	set  a
	      server-nonresponse timeout in seconds.  If a mailserver does not
	      send a greeting message or respond to  commands  for  the	 given
	      number of seconds, fetchmail will hang up on it.	Without such a
	      timeout fetchmail might hang indefinitely trying to  fetch  mail
	      from  a  down  host.   This would be particularly annoying for a
	      fetchmail running in the background.  There is a default timeout
	      which  fetchmail -V will report.	If a given connection receives
	      too many timeouts in  succession,	 fetchmail  will  consider  it
	      wedged  and stop retrying.  The calling user will be notified by
	      email if this happens.

       --plugin <command>
	      (Keyword: plugin) The plugin option allows you to use an	exter‐
	      nal  program to establish the TCP connection.  This is useful if
	      you want to use SSL, ssh, or need some special firewalling  set‐
	      up.   The	 program will be looked up in $PATH and can optionally
	      be passed the hostname and port as arguments using "%h" and "%p"
	      respectively (note that the interpolation logic is rather primi‐
	      tive, and these token must be bounded by whitespace or beginning
	      of  string or end of string).  Fetchmail will write to the plug‐
	      in's stdin and read from the plugin's stdout.

       --plugout <command>
	      (Keyword: plugout) Identical to the  plugin  option  above,  but
	      this  one	 is used for the SMTP connections (which will probably
	      not need it, so it has been separated from plugin).

       -r <name> | --folder <name>
	      (Keyword: folder[s]) Causes a specified non-default mail	folder
	      on  the  mailserver  (or	comma-separated list of folders) to be
	      retrieved.  The syntax of the folder name	 is  server-dependent.
	      This option is not available under POP3, ETRN, or ODMR.

       --tracepolls
	      (Keyword:	 tracepolls)  Tell fetchmail to poll trace information
	      in the form 'polling %s account  %s'  and	 'folder  %s'  to  the
	      Received	line  it generates, where the %s parts are replaced by
	      the user's remote name, the poll label, and the folder (mailbox)
	      where  available (the Received header also normally includes the
	      server's true name).  This can be used to facilitate  mail  fil‐
	      tering  based  on	 the  account  it  is being received from. The
	      folder information is written only since version 6.3.4.

       --ssl  (Keyword: ssl) Causes the connection to the mail	server	to  be
	      encrypted	 via  SSL.   Connect to the server using the specified
	      base protocol over a connection  secured	by  SSL.  This	option
	      defeats  TLS  negotiation.  Use --sslcertck to validate the cer‐
	      tificates presented by the server.

	      Note that fetchmail may still try to negotiate TLS even if  this
	      option is not given. You can use the --sslproto option to defeat
	      this behavior or tell fetchmail to negotiate  a  particular  SSL
	      protocol.

	      If no port is specified, the connection is attempted to the well
	      known port of the SSL version of the  base  protocol.   This  is
	      generally a different port than the port used by the base proto‐
	      col.  For IMAP, this is port 143 for the clear protocol and port
	      993  for	the SSL secured protocol, for POP3, it is port 110 for
	      the clear text and port 995 for the encrypted variant.

	      If your system lacks the corresponding  entries  from  /etc/ser‐
	      vices,  see  the	--service  option and specify the numeric port
	      number as given in the previous paragraph (unless your  ISP  had
	      directed you to different ports, which is uncommon however).

       --sslcert <name>
	      (Keyword:	 sslcert)  Specifies  the file name of the client side
	      public SSL certificate.  Some SSL encrypted servers may  require
	      client  side  keys and certificates for authentication.  In most
	      cases, this is optional.	This specifies	the  location  of  the
	      public key certificate to be presented to the server at the time
	      the SSL session is established.  It is not required (but may  be
	      provided)	 if  the server does not require it.  Some servers may
	      require it, some servers may request it but not require it,  and
	      some servers may not request it at all.  It may be the same file
	      as the private key (combined key and certificate file) but  this
	      is not recommended.

	      NOTE: If you use client authentication, the user name is fetched
	      from the certificate's CommonName and  overrides	the  name  set
	      with --user.

       --sslkey <name>
	      (Keyword:	 sslkey)  Specifies  the  file name of the client side
	      private SSL key.	Some SSL encrypted servers may require	client
	      side  keys  and certificates for authentication.	In most cases,
	      this is optional.	 This specifies the location  of  the  private
	      key  used	 to  sign transactions with the server at the time the
	      SSL session is established.  It is not required (but may be pro‐
	      vided)  if  the  server  does  not require it.  Some servers may
	      require it, some servers may request it but not require it,  and
	      some servers may not request it at all.  It may be the same file
	      as the public key (combined key and certificate file)  but  this
	      is  not  recommended.   If  a password is required to unlock the
	      key, it will be prompted for at the time just  prior  to	estab‐
	      lishing  the session to the server.  This can cause some compli‐
	      cations in daemon mode.

       --sslproto <name>
	      (Keyword: sslproto) Forces an SSL or TLS protocol. Possible val‐
	      ues  are	'SSL2',	 'SSL3',  'SSL23', and 'TLS1'. Try this if the
	      default handshake does not work for your server. Use this option
	      with 'TLS1' to enforce a TLS connection. To defeat opportunistic
	      TLSv1 negotiation when the server advertises STARTTLS  or	 STLS,
	      use  ''.	This option, even if the argument is the empty string,
	      will also suppress the diagnostic 'SERVER: opportunistic upgrade
	      to  TLS.'	 message in verbose mode. The default is to try appro‐
	      priate protocols depending on context.

       --sslcertck
	      (Keyword: sslcertck) Causes  fetchmail  to  strictly  check  the
	      server  certificate  against a set of local trusted certificates
	      (see the sslcertpath option). If the server  certificate	cannot
	      be  obtained  or	is  not	 signed	 by  one  of  the trusted ones
	      (directly or indirectly), the SSL connection will fail,  regard‐
	      less  of the sslfingerprint option.  Note that CRL are only sup‐
	      ported in OpenSSL 0.9.7 and newer! Your system clock should also
	      be reasonably accurate when using this option.

	      Note  that this optional behavior may become default behavior in
	      future fetchmail versions.

       --sslcertpath <directory>
	      (Keyword: sslcertpath) Sets the directory fetchmail uses to look
	      up  local certificates. The default is your OpenSSL default one.
	      The directory must be hashed as OpenSSL expects it - every  time
	      you  add	or  modify a certificate in the directory, you need to
	      use the c_rehash tool (which comes with OpenSSL  in  the	tools/
	      subdirectory).

       --sslcommonname <common name>
	      (Keyword:	 sslcommonname)	 Use  of  this	option is discouraged.
	      Before using it, contact	the  administrator  of	your  upstream
	      server  and ask for a proper SSL certificate to be used. If that
	      cannot be attained, this option can be used to specify the  name
	      (CommonName)  that  fetchmail expects on the server certificate.
	      A correctly configured server will have this set to the hostname
	      by  which it is reached, and by default fetchmail will expect as
	      much. Use this option when the CommonName is set to  some	 other
	      value,  to  avoid	 the "Server CommonName mismatch" warning, and
	      only if the upstream server can't be made to use proper certifi‐
	      cates.

       --sslfingerprint <fingerprint>
	      (Keyword:	 sslfingerprint) Specify the fingerprint of the server
	      key (an MD5 hash of the key) in hexadecimal notation with colons
	      separating  groups  of two digits. The letter hex digits must be
	      in upper case. This is the default format OpenSSL uses, and  the
	      one fetchmail uses to report the fingerprint when an SSL connec‐
	      tion is established. When this is specified, fetchmail will com‐
	      pare the server key fingerprint with the given one, and the con‐
	      nection will fail	 if  they  do  not  match  regardless  of  the
	      sslcertck	 setting.  The	connection will also fail if fetchmail
	      cannot obtain an SSL certificate from the server.	 This  can  be
	      used  to prevent man-in-the-middle attacks, but the finger print
	      from the server needs to be obtained or verified over  a	secure
	      channel,	and  certainly	not  over the same Internet connection
	      that fetchmail would use.

	      Using this option will prevent printing certificate verification
	      errors as long as --sslcertck is unset.

	      To  obtain  the  fingerprint of a certificate stored in the file
	      cert.pem, try:

		   openssl x509 -in cert.pem -noout -md5 -fingerprint

	      For details, see x509(1ssl).

   Delivery Control Options
       -S <hosts> | --smtphost <hosts>
	      (Keyword: smtp[host]) Specify a hunt list of  hosts  to  forward
	      mail  to	(one  or  more	hostnames, comma-separated). Hosts are
	      tried in list order; the first one that is up becomes  the  for‐
	      warding target for the current run.  If this option is not spec‐
	      ified, 'localhost' is used as the default.   Each	 hostname  may
	      have  a port number following the host name.  The port number is
	      separated from the host name by a slash;	the  default  port  is
	      "smtp".	If you specify an absolute path name (beginning with a
	      /), it will be interpreted as the name of a UNIX socket  accept‐
	      ing  LMTP	 connections  (such  as is supported by the Cyrus IMAP
	      daemon) Example:

		   --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp

	      This option can be used with ODMR, and  will  make  fetchmail  a
	      relay between the ODMR server and SMTP or LMTP receiver.

       --fetchdomains <hosts>
	      (Keyword: fetchdomains) In ETRN or ODMR mode, this option speci‐
	      fies the list of domains the server should ship  mail  for  once
	      the connection is turned around.	The default is the FQDN of the
	      machine running fetchmail.

       -D <domain> | --smtpaddress <domain>
	      (Keyword: smtpaddress) Specify the  domain  to  be  appended  to
	      addresses	 in  RCPT  TO  lines shipped to SMTP. When this is not
	      specified, the name of the SMTP server (as specified  by	--smt‐
	      phost)  is  used	for SMTP/LMTP and 'localhost' is used for UNIX
	      socket/BSMTP.

       --smtpname <user@domain>
	      (Keyword: smtpname) Specify the domain and user  to  be  put  in
	      RCPT  TO lines shipped to SMTP.  The default user is the current
	      local user.

       -Z <nnn> | --antispam <nnn[, nnn]...>
	      (Keyword: antispam) Specifies the list of	 numeric  SMTP	errors
	      that  are	 to  be	 interpreted as a spam-block response from the
	      listener.	 A value of -1 disables this option.  For the command-
	      line option, the list values should be comma-separated.

       -m <command> | --mda <command>
	      (Keyword:	 mda)  You  can	 force	mail  to  be  passed to an MDA
	      directly (rather than forwarded to port 25) with the --mda or -m
	      option.

	      To  avoid losing mail, use this option only with MDAs like mail‐
	      drop or MTAs like sendmail that return a nonzero status on disk-
	      full  and	 other	resource-exhaustion errors; the nonzero status
	      tells fetchmail that delivery failed and	prevents  the  message
	      from being deleted off the server.

	      If  fetchmail is running as root, it sets its user id to that of
	      the target user while delivering mail through an MDA.  Some pos‐
	      sible  MDAs  are "/usr/sbin/sendmail -i -f %F -- %T" (Note: some
	      several older or vendor sendmail	versions  mistake  --  for  an
	      address,	rather than an indicator to mark the end of the option
	      arguments), "/usr/bin/deliver" and  "/usr/bin/maildrop  -d  %T".
	      Local  delivery  addresses will be inserted into the MDA command
	      wherever you place a %T; the mail message's From address will be
	      inserted where you place an %F.

	      DO  NOT  ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!  For both
	      %T and %F, fetchmail encloses the	 addresses  in	single	quotes
	      ('),  after  removing any single quotes they may contain, before
	      the MDA command is passed to the shell.

	      Do NOT use an MDA invocation that dispatches on the contents  of
	      To/Cc/Bcc, like "sendmail -i -t" or "qmail-inject", it will cre‐
	      ate mail loops and bring the just wrath of many postmasters down
	      upon  your head.	This is one of the most frequent configuration
	      errors!

	      Also, do not try to combine multidrop mode with an MDA  such  as
	      maildrop	that can only accept one address, unless your upstream
	      stores one copy of the message per recipient and transports  the
	      envelope recipient in a header; you will lose mail.

	      The  well-known  procmail(1)  package  is very hard to configure
	      properly, it has a very nasty "fall through to  the  next	 rule"
	      behavior on delivery errors (even temporary ones, such as out of
	      disk space if another user's  mail  daemon  copies  the  mailbox
	      around  to  purge old messages), so your mail will end up in the
	      wrong mailbox sooner or later. The proper procmail configuration
	      is outside the scope of this document. Using maildrop(1) is usu‐
	      ally much easier, and many users find the filter syntax used  by
	      maildrop easier to understand.

	      Finally,	we  strongly  advise that you do not use qmail-inject.
	      The command line interface  is  non-standard  without  providing
	      benefits	for  typical  use,  and fetchmail makes no attempts to
	      accomodate qmail-inject's deviations from the standard. Some  of
	      qmail-inject's command-line and environment options are actually
	      dangerous and can cause broken threads,  non-detected  duplicate
	      messages and forwarding loops.

       --lmtp (Keyword:	 lmtp)	Cause  delivery	 via LMTP (Local Mail Transfer
	      Protocol).  A service host and port must be explicitly specified
	      on  each	host  in  the  smtphost	 hunt list (see above) if this
	      option is selected; the default port 25 will (in accordance with
	      RFC 2033) not be accepted.

       --bsmtp <filename>
	      (keyword: bsmtp) Append fetched mail to a BSMTP file.  This sim‐
	      ply contains the SMTP commands that would normally be  generated
	      by  fetchmail  when passing mail to an SMTP listener daemon.  An
	      argument of '-' causes the mail to be written to	standard  out‐
	      put.  Note that fetchmail's reconstruction of MAIL FROM and RCPT
	      TO lines is not guaranteed correct; the caveats discussed	 under
	      THE USE AND ABUSE OF MULTIDROP MAILBOXES below apply.

   Resource Limit Control Options
       -l <maxbytes> | --limit <maxbytes>
	      (Keyword: limit) Takes a maximum octet size argument, where 0 is
	      the default and also the special value designating  "no  limit".
	      If  nonzero,  messages larger than this size will not be fetched
	      and will be left on the  server  (in  foreground	sessions,  the
	      progress	messages will note that they are "oversized").	If the
	      fetch protocol permits (in particular, under IMAP or POP3	 with‐
	      out the fetchall option) the message will not be marked seen.

	      An  explicit  --limit  of 0 overrides any limits set in your run
	      control file. This option	 is  intended  for  those  needing  to
	      strictly	control fetch time due to expensive and variable phone
	      rates.

	      Combined with --limitflush, it can be used to  delete  oversized
	      messages	waiting on a server.  In daemon mode, oversize notifi‐
	      cations are mailed to  the  calling  user	 (see  the  --warnings
	      option). This option does not work with ETRN or ODMR.

       -w <interval> | --warnings <interval>
	      (Keyword: warnings) Takes an interval in seconds.	 When you call
	      fetchmail with a 'limit' option in daemon	 mode,	this  controls
	      the  interval  at	 which	warnings  about oversized messages are
	      mailed to the calling user (or the user specified by the	'post‐
	      master'  option).	 One such notification is always mailed at the
	      end of  the  the	first  poll  that  the	oversized  message  is
	      detected.	 Thereafter, re-notification is suppressed until after
	      the warning interval elapses (it will take place at the  end  of
	      the first following poll).

       -b <count> | --batchlimit <count>
	      (Keyword:	 batchlimit)  Specify  the  maximum number of messages
	      that will be shipped to an SMTP listener before  the  connection
	      is deliberately torn down and rebuilt (defaults to 0, meaning no
	      limit).  An explicit --batchlimit of 0 overrides any limits  set
	      in  your run control file.  While sendmail(8) normally initiates
	      delivery of a message immediately after  receiving  the  message
	      terminator,  some	 SMTP  listeners are not so prompt.  MTAs like
	      smail(8) may wait till the  delivery  socket  is	shut  down  to
	      deliver.	 This  may  produce  annoying delays when fetchmail is
	      processing very large batches.  Setting the batch limit to  some
	      nonzero  size  will  prevent these delays.  This option does not
	      work with ETRN or ODMR.

       -B <number> | --fetchlimit <number>
	      (Keyword: fetchlimit) Limit the number of messages accepted from
	      a	 given server in a single poll.	 By default there is no limit.
	      An explicit --fetchlimit of 0 overrides any limits set  in  your
	      run control file.	 This option does not work with ETRN or ODMR.

       --fetchsizelimit <number>
	      (Keyword:	 fetchsizelimit) Limit the number of sizes of messages
	      accepted from a given server  in	a  single  transaction.	  This
	      option  is useful in reducing the delay in downloading the first
	      mail when there are too many mails in the mailbox.  By  default,
	      the  limit is 100.  If set to 0, sizes of all messages are down‐
	      loaded at the start.  This option does not  work	with  ETRN  or
	      ODMR.  For POP3, the only valid non-zero value is 1.

       --fastuidl <number>
	      (Keyword: fastuidl) Do a binary instead of linear search for the
	      first unseen UID. Binary search avoids downloading the  UIDs  of
	      all  mails.  This	 saves	time (especially in daemon mode) where
	      downloading the same set of UIDs in each	poll  is  a  waste  of
	      bandwidth.  The  number 'n' indicates how rarely a linear search
	      should be done. In daemon mode, linear search is used once  fol‐
	      lowed  by	 binary searches in 'n-1' polls if 'n' is greater than
	      1; binary search is always used if 'n' is 1;  linear  search  is
	      always  used  if	'n' is 0. In non-daemon mode, binary search is
	      used if 'n' is 1; otherwise linear search is used.  The  default
	      value of 'n' is 4.  This option works with POP3 only.

       -e <count> | --expunge <count>
	      (keyword:	 expunge) Arrange for deletions to be made final after
	      a given number of messages.  Under POP2 or POP3, fetchmail  can‐
	      not  make	 deletions  final  without sending QUIT and ending the
	      session -- with this option on, fetchmail will break a long mail
	      retrieval session into multiple sub-sessions, sending QUIT after
	      each sub-session. This is a good defense against line  drops  on
	      POP3  servers.  Under IMAP, fetchmail normally issues an EXPUNGE
	      command after each deletion in order to force the deletion to be
	      done  immediately.   This	 is safest when your connection to the
	      server is flaky and expensive, as it avoids resending  duplicate
	      mail after a line hit.  However, on large mailboxes the overhead
	      of re-indexing after every message can slam  the	server	pretty
	      hard,  so	 if  your  connection  is  reliable  it	 is good to do
	      expunges less frequently.	 Also note that some servers enforce a
	      delay  of a few seconds after each quit, so fetchmail may not be
	      able to get back in immediately after an expunge -- you may  see
	      "lock  busy"  errors if this happens. If you specify this option
	      to an integer N, it tells fetchmail to only  issue  expunges  on
	      every  Nth  delete.   An	argument  of  zero suppresses expunges
	      entirely (so no expunges at all will be done until  the  end  of
	      run).  This option does not work with ETRN or ODMR.

   Authentication Options
       -u <name> | --user <name> | --username <name>
	      (Keyword:	 user[name])  Specifies	 the user identification to be
	      used when logging in to the mailserver.	The  appropriate  user
	      identification  is  both server and user-dependent.  The default
	      is your login name on the client machine that is running	fetch‐
	      mail.  See USER AUTHENTICATION below for a complete description.

       -I <specification> | --interface <specification>
	      (Keyword: interface) Require that a specific interface device be
	      up and have a specific local or remote IPv4 (IPv6	 is  not  sup‐
	      ported  by  this	option yet) address (or range) before polling.
	      Frequently fetchmail is used  over  a  transient	point-to-point
	      TCP/IP  link  established	 directly  to a mailserver via SLIP or
	      PPP.  That is a  relatively  secure  channel.   But  when	 other
	      TCP/IP  routes  to  the  mailserver exist (e.g. when the link is
	      connected to an alternate ISP), your username and	 password  may
	      be vulnerable to snooping (especially when daemon mode automati‐
	      cally polls for mail, shipping a clear password over the net  at
	      predictable  intervals).	 The --interface option may be used to
	      prevent this.  When the specified link is not up or is not  con‐
	      nected  to  a matching IP address, polling will be skipped.  The
	      format is:

		   interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]

	      The field before the first slash is  the	interface  name	 (i.e.
	      sl0,  ppp0  etc.).   The	field  before  the second slash is the
	      acceptable IP address.  The field after the second  slash	 is  a
	      mask  which  specifies a range of IP addresses to accept.	 If no
	      mask is  present	255.255.255.255	 is  assumed  (i.e.  an	 exact
	      match).  This option is currently only supported under Linux and
	      FreeBSD. Please see the monitor section for  below  for  FreeBSD
	      specific information.

	      Note  that  this	option	may be removed from a future fetchmail
	      version.

       -M <interface> | --monitor <interface>
	      (Keyword: monitor) Daemon mode can cause transient  links	 which
	      are  automatically taken down after a period of inactivity (e.g.
	      PPP links) to remain up indefinitely.  This option identifies  a
	      system  TCP/IP  interface	 to  be monitored for activity.	 After
	      each poll interval, if the link is up but no other activity  has
	      occurred	on  the link, then the poll will be skipped.  However,
	      when fetchmail is woken up by a signal,  the  monitor  check  is
	      skipped  and the poll goes through unconditionally.  This option
	      is currently only supported under Linux and  FreeBSD.   For  the
	      monitor  and  interface options to work for non root users under
	      FreeBSD, the fetchmail binary must be installed SGID kmem.  This
	      would  be a security hole, but fetchmail runs with the effective
	      GID set to that of the kmem group only when  interface  data  is
	      being collected.

	      Note  that  this	option	may be removed from a future fetchmail
	      version.

       --auth <type>
	      (Keyword: auth[enticate]) This option permits you to specify  an
	      authentication type (see USER AUTHENTICATION below for details).
	      The possible values are  any,  password,	kerberos_v5,  kerberos
	      (or, for excruciating exactness, kerberos_v4), gssapi, cram-md5,
	      otp, ntlm, msn (only for POP3), external (only  IMAP)  and  ssh.
	      When any (the default) is specified, fetchmail tries first meth‐
	      ods that	don't  require	a  password  (EXTERNAL,	 GSSAPI,  KER‐
	      BEROS IV,	 KERBEROS 5); then it looks for methods that mask your
	      password (CRAM-MD5, X-OTP - note that NTLM and MSN are not auto‐
	      probed for POP3 and MSN is only supported for POP3); and only if
	      the server doesn't support any of those will it ship your	 pass‐
	      word  en	clair.	 Other	values	may  be	 used to force various
	      authentication methods (ssh  suppresses  authentication  and  is
	      thus useful for IMAP PREAUTH).  (external suppresses authentica‐
	      tion and is thus useful for IMAP	EXTERNAL).   Any  value	 other
	      than password, cram-md5, ntlm, msn or otp suppresses fetchmail's
	      normal inquiry for a password.  Specify ssh when you  are	 using
	      an  end-to-end  secure connection such as an ssh tunnel; specify
	      external when you use TLS with client authentication and specify
	      gssapi  or  kerberos_v4 if you are using a protocol variant that
	      employs GSSAPI or	 K4.   Choosing	 KPOP  protocol	 automatically
	      selects Kerberos authentication.	This option does not work with
	      ETRN.

   Miscellaneous Options
       -f <pathname> | --fetchmailrc <pathname>
	      Specify a non-default name for the  ~/.fetchmailrc  run  control
	      file.   The pathname argument must be either "-" (a single dash,
	      meaning to read the configuration	 from  standard	 input)	 or  a
	      filename.	  Unless the --version option is also on, a named file
	      argument	must  have  permissions	 no  more   open   than	  0700
	      (u=rwx,g=,o=) or else be /dev/null.

       -i <pathname> | --idfile <pathname>
	      (Keyword:	 idfile)  Specify  an alternate name for the .fetchids
	      file used to save message UIDs.  NOTE:  since  fetchmail	6.3.0,
	      write access to the directory containing the idfile is required,
	      as fetchmail writes a temporary file and	renames	 it  into  the
	      place  of	 the  real  idfile only if the temporary file has been
	      written successfully. This avoids the truncation of idfiles when
	      running out of disk space.

       --pidfile <pathname>
	      (Keyword:	 pidfile; since fetchmail v6.3.4) Override the default
	      location of the PID file. Default: see "ENVIRONMENT" below.

       -n | --norewrite
	      (Keyword: no rewrite) Normally, fetchmail edits RFC-822  address
	      headers  (To,  From,  Cc,	 Bcc, and Reply-To) in fetched mail so
	      that any mail IDs local to  the  server  are  expanded  to  full
	      addresses	 (@  and  the mailserver hostname are appended).  This
	      enables replies on the client to get addressed correctly (other‐
	      wise  your  mailer might think they should be addressed to local
	      users on the client machine!).  This  option  disables  the  re‐
	      write.   (This option is provided to pacify people who are para‐
	      noid about having an MTA edit mail headers and want to know they
	      can  prevent it, but it is generally not a good idea to actually
	      turn off rewrite.)  When using ETRN or ODMR, the rewrite	option
	      is ineffective.

       -E <line> | --envelope <line>
	      (Keyword: envelope; Multidrop only)
	      In the configuration file, an enhanced syntax is used:
	      envelope [<count>] <line>

	      This  option  changes  the header fetchmail assumes will carry a
	      copy of the mail's envelope address.  Normally this is  'X-Enve‐
	      lope-To'. Other typically found headers to carry envelope infor‐
	      mation are 'X-Original-To' and 'Delivered-To'.  Now, since these
	      headers  are  not standardized, practice varies. See the discus‐
	      sion of multidrop address handling below.	 As  a	special	 case,
	      'envelope "Received"' enables parsing of sendmail-style Received
	      lines.  This is the default, but discouraged because it  is  not
	      fully reliable.

	      Note  that  fetchmail  expects the Received-line to be in a spe‐
	      cific format: It must contain "by host for address", where  host
	      must match one of the mailserver names that fetchmail recognizes
	      for the account in question.

	      The optional count argument (only available in the configuration
	      file) determines how many header lines of this kind are skipped.
	      A count of 1 means: skip the first, take the second. A count  of
	      2 means: skip the first and second, take the third, and so on.

       -Q <prefix> | --qvirtual <prefix>
	      (Keyword:	 qvirtual;  Multidrop only) The string prefix assigned
	      to this option will be removed from the user name found  in  the
	      header  specified	 with  the  envelope option (before doing mul‐
	      tidrop name mapping or localdomain checking, if either is appli‐
	      cable). This option is useful if you are using fetchmail to col‐
	      lect the mail for an entire domain and your ISP  (or  your  mail
	      redirection provider) is using qmail.  One of the basic features
	      of qmail is the

	      'Delivered-To:'

	      message header.  Whenever qmail delivers a message  to  a	 local
	      mailbox it puts the username and hostname of the envelope recip‐
	      ient on this line.  The major reason for this is to prevent mail
	      loops.   To  set	up qmail to batch mail for a disconnected site
	      the ISP-mailhost will have normally put that site in its 'Virtu‐
	      alhosts'	control	 file  so  it  will  add  a prefix to all mail
	      addresses for this site. This results in	mail  sent  to	'user‐
	      name@userhost.userdom.dom.com'  having a 'Delivered-To:' line of
	      the form:

	      Delivered-To: mbox-userstr-username@userhost.example.com

	      The ISP can make the 'mbox-userstr-' prefix anything they choose
	      but  a  string  matching the user host name is likely.  By using
	      the option 'envelope Delivered-To:' you can make fetchmail reli‐
	      ably  identify  the original envelope recipient, but you have to
	      strip the 'mbox-userstr-' prefix to deliver to the correct user.
	      This is what this option is for.

       --configdump
	      Parse   the  ~/.fetchmailrc  file,  interpret  any  command-line
	      options specified, and dump a configuration report  to  standard
	      output.  The configuration report is a data structure assignment
	      in the language Python.  This option is meant to be used with an
	      interactive ~/.fetchmailrc editor like fetchmailconf, written in
	      Python.

   Removed Options
       -T | --netsec
	      Removed before version 6.3.0, the required underlying inet6_apps
	      library had been discontinued and is no longer available.

USER AUTHENTICATION AND ENCRYPTION
       All  modes  except  ETRN	 require  authentication  of the client to the
       server.	Normal user authentication in fetchmail is very much like  the
       authentication  mechanism  of ftp(1).  The correct user-id and password
       depend upon the underlying security system at the mailserver.

       If the mailserver is a Unix machine on which you have an ordinary  user
       account,	 your regular login name and password are used with fetchmail.
       If you use the same login name  on  both	 the  server  and  the	client
       machines,  you  needn't	worry  about  specifying a user-id with the -u
       option -- the default behavior is to use your login name on the	client
       machine	as  the user-id on the server machine.	If you use a different
       login name on the server machine, specify that login name with  the  -u
       option.	 e.g. if your login name is 'jsmith' on a machine named 'mail‐
       grunt', you would start fetchmail as follows:

	      fetchmail -u jsmith mailgrunt

       The default behavior of fetchmail is to prompt you for your  mailserver
       password	 before the connection is established.	This is the safest way
       to use fetchmail and ensures that your password	will  not  be  compro‐
       mised.  You may also specify your password in your ~/.fetchmailrc file.
       This is convenient when using fetchmail in daemon mode or with scripts.

   Using netrc files
       If you do not specify a password, and fetchmail cannot extract one from
       your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
       directory before requesting one interactively; if an entry matching the
       mailserver is found in that file, the password will be used.  Fetchmail
       first looks for a match on poll name; if it finds none, it checks for a
       match  on  via name.  See the ftp(1) man page for details of the syntax
       of the ~/.netrc file.  To show a practical example, a .netrc might look
       like this:

	      machine hermes.example.org
	      login joe
	      password topsecret

       You  can	 repeat this block with different user information if you need
       to provide more than one password.

       This feature may allow you to avoid duplicating password information in
       more than one file.

       On mailservers that do not provide ordinary user accounts, your user-id
       and password are usually assigned by the server administrator when  you
       apply  for  a mailbox on the server.  Contact your server administrator
       if you don't know the correct user-id and  password  for	 your  mailbox
       account.

POP3 VARIANTS
       Early  versions	of  POP3  (RFC1081, RFC1225) supported a crude form of
       independent authentication using the  rhosts  file  on  the  mailserver
       side.   Under  this  RPOP  variant, a fixed per-user ID equivalent to a
       password was sent in clear over a link to a  reserved  port,  with  the
       command	RPOP  rather  than  PASS to alert the server that it should do
       special checking.  RPOP is supported  by	 fetchmail  (you  can  specify
       'protocol RPOP' to have the program send 'RPOP' rather than 'PASS') but
       its use is strongly discouraged, and support will  be  removed  from  a
       future fetchmail version.  This facility was vulnerable to spoofing and
       was withdrawn in RFC1460.

       RFC1460 introduced APOP authentication.	In this variant of  POP3,  you
       register	 an  APOP  password  on your server host (on some servers, the
       program to do this is called popauth(8)).  You put the same password in
       your ~/.fetchmailrc file.  Each time fetchmail logs in, it sends an MD5
       hash of your password and the server greeting time to the server, which
       can verify it by checking its authorization database.

       Note  that  APOP	 is no longer considered resistant against man-in-the-
       middle attacks.

   RETR or TOP
       fetchmail makes some efforts to make the server	believe	 messages  had
       not  been  retrieved,  by  using the TOP command with a large number of
       lines when possible.  TOP is a command that retrieves the  full	header
       and  a  fetchmail-specified  amount  of	body lines. It is optional and
       therefore not implemented by all servers, and some are known to	imple‐
       ment  it	 improperly.  On  many servers however, the RETR command which
       retrieves the full message with header and body, sets the  "seen"  flag
       (for instance, in a web interface), whereas the TOP command does not do
       that.

       fetchmail will always use  the  RETR  command  if  "fetchall"  is  set.
       fetchmail will also use the RETR command if "keep" is set and "uidl" is
       unset.  Finally, fetchmail will use the	RETR  command  on  Maillennium
       POP3/PROXY  servers  (used by Comcast) to avoid a deliberate TOP misin‐
       terpretation in this server that causes message corruption.

       In all other cases, fetchmail will use the TOP  command.	 This  implies
       that in "keep" setups, "uidl" must be set if "TOP" is desired.

       Note  that  this	 description is true for the current version of fetch‐
       mail, but the behavior may change in future  versions.  In  particular,
       fetchmail  may  prefer  the RETR command because the TOP command causes
       much grief on some servers and is only optional.

ALTERNATE AUTHENTICATION FORMS
       If your fetchmail was built with Kerberos support and you specify  Ker‐
       beros  authentication  (either  with  --auth or the .fetchmailrc option
       authenticate kerberos_v4) it will try to get a Kerberos ticket from the
       mailserver at the start of each query.  Note: if either the pollname or
       via name is 'hesiod', fetchmail will try to use Hesiod to look  up  the
       mailserver.

       If  you	use  POP3  or  IMAP with GSSAPI authentication, fetchmail will
       expect the server to have RFC1731- or RFC1734-conforming	 GSSAPI	 capa‐
       bility, and will use it.	 Currently this has only been tested over Ker‐
       beros V, so you're expected to already have a  ticket-granting  ticket.
       You  may	 pass  a username different from your principal name using the
       standard --user command or by the .fetchmailrc option user.

       If your IMAP daemon returns the PREAUTH response in its greeting	 line,
       fetchmail  will	notice	this  and skip the normal authentication step.
       This can be useful, e.g. if you start imapd explicitly using  ssh.   In
       this  case  you can declare the authentication value 'ssh' on that site
       entry to stop .fetchmail from asking you for a password when it	starts
       up.

       If you use client authentication with TLS1 and your IMAP daemon returns
       the AUTH=EXTERNAL response, fetchmail will notice this and will use the
       authentication  shortcut and will not send the passphrase. In this case
       you can declare the authentication value 'external'
	on that site to stop fetchmail from asking you for a password when  it
       starts up.

       If  you are using POP3, and the server issues a one-time-password chal‐
       lenge conforming to RFC1938, fetchmail will use your password as a pass
       phrase  to  generate the required response. This avoids sending secrets
       over the net unencrypted.

       Compuserve's RPA authentication is supported. If	 you  compile  in  the
       support,	 fetchmail  will try to perform an RPA pass-phrase authentica‐
       tion instead of sending over the password en clair if it detects "@com‐
       puserve.com" in the hostname.

       If  you are using IMAP, Microsoft's NTLM authentication (used by Micro‐
       soft Exchange) is supported. If you compile in the  support,  fetchmail
       will try to perform an NTLM authentication (instead of sending over the
       password en clair) whenever the server returns AUTH=NTLM in  its	 capa‐
       bility	response.   Specify  a	user  option  value  that  looks  like
       'user@domain': the part to the left of the @  will  be  passed  as  the
       username and the part to the right as the NTLM domain.

   Secure Socket Layers (SSL) and Transport Layer Security (TLS)
       You  can	 access SSL encrypted services by specifying the --ssl option.
       You can also do this using the "ssl" user option	 in  the  .fetchmailrc
       file. With SSL encryption enabled, queries are initiated over a connec‐
       tion after negotiating an SSL session, and the connection fails if  SSL
       cannot  be negotiated.  Some services, such as POP3 and IMAP, have dif‐
       ferent well known ports defined for the SSL  encrypted  services.   The
       encrypted  ports will be selected automatically when SSL is enabled and
       no explicit port is specified. The --sslproto option  can  be  used  to
       select  the SSL protocols (default: v2 or v3).  The --sslcertck command
       line or sslcertck run control file  option  should  be  used  to	 force
       strict certificate checking - see below.

       If  SSL is not configured, fetchmail will usually opportunistically try
       to use TLS. TLS can be enforced by using --sslproto "TLS1". TLS connec‐
       tions  use the same port as the unencrypted version of the protocol and
       negotiate TLS via special parameter. The --sslcertck  command  line  or
       sslcertck  run  control file option should be used to force strict cer‐
       tificate checking - see below.

       --sslcertck recommended: When connecting to an  SSL  or	TLS  encrypted
       server, the server presents a certificate to the client for validation.
       The certificate is checked to verify that the common name in  the  cer‐
       tificate	 matches  the  name of the server being contacted and that the
       effective and expiration dates in the certificate indicate that	it  is
       currently  valid.   If  any  of these checks fail, a warning message is
       printed, but the connection continues.  The server certificate does not
       need  to	 be  signed  by any specific Certifying Authority and may be a
       "self-signed" certificate. If the --sslcertck command  line  option  or
       sslcertck run control file option is used, fetchmail will instead abort
       if any of these checks fail. Use of the sslcertck or --sslcertck option
       is advised.

       Some  SSL  encrypted  servers may request a client side certificate.  A
       client side public SSL certificate and private SSL key  may  be	speci‐
       fied.   If  requested  by the server, the client certificate is sent to
       the server for validation.  Some servers may  require  a	 valid	client
       certificate and may refuse connections if a certificate is not provided
       or if the certificate is not valid.  Some servers  may  require	client
       side  certificates be signed by a recognized Certifying Authority.  The
       format for the key files and the certificate files is that required  by
       the underlying SSL libraries (OpenSSL in the general case).

       A  word	of care about the use of SSL: While above mentioned setup with
       self-signed server certificates retrieved over the  wires  can  protect
       you  from  a  passive  eavesdropper,  it doesn't help against an active
       attacker. It's clearly an improvement over  sending  the	 passwords  in
       clear, but you should be aware that a man-in-the-middle attack is triv‐
       ially possible (in particular with tools such  as  dsniff,  http://mon‐
       key.org/~dugsong/dsniff/).   Use	 of strict certificate checking with a
       certification authority recognized by server and client, or perhaps  of
       an  SSH	tunnel (see below for some examples) is preferable if you care
       seriously about the security of your mailbox and passwords.

   ESMTP AUTH
       fetchmail also supports authentication  to  the	ESMTP  server  on  the
       client  side  according	to  RFC 2554.  You can specify a name/password
       pair to be used with the keywords 'esmtpname' and 'esmtppassword';  the
       former defaults to the username of the calling user.

DAEMON MODE
   Introducing the daemon mode
       In daemon mode, fetchmail puts itself into the background and runs for‐
       ever, querying each specified  host  and	 then  sleeping	 for  a	 given
       polling interval.

   Starting the daemon mode
       There  are  several  ways to make fetchmail work in daemon mode. On the
       command line, --daemon <interval> or -d <interval> option  runs	fetch‐
       mail  in	 daemon	 mode.	You must specify a numeric argument which is a
       polling interval in seconds.

       Example: simply invoking

	      fetchmail -d 900

       will, therefore, poll all the hosts described  in  your	~/.fetchmailrc
       file (except those explicitly excluded with the 'skip' verb) once every
       15 minutes.

       It is also possible to set a polling interval  in  your	~/.fetchmailrc
       file  by saying 'set daemon <interval>', where <interval> is an integer
       number of seconds.  If you do this, fetchmail will always start in dae‐
       mon mode unless you override it with the command-line option --daemon 0
       or -d0.

       Only one daemon process is permitted per user; in daemon	 mode,	fetch‐
       mail  sets  up a per-user lockfile to guarantee this.  (You can however
       cheat and set the FETCHMAILHOME environment variable to	overcome  this
       setting,	 but  in that case, it is your responsibility to make sure you
       aren't polling the same server with two processes at the same time.)

   Awakening the background daemon
       Normally, calling fetchmail with a daemon in  the  background  sends  a
       wake-up	signal	to the daemon and quits without output. The background
       daemon then starts its next poll cycle immediately.  The	 wake-up  sig‐
       nal, SIGUSR1, can also be sent manually. The wake-up action also clears
       any 'wedged' flags indicating  that  connections	 have  wedged  due  to
       failed authentication or multiple timeouts.

   Terminating the background daemon
       The  option --quit will kill a running daemon process instead of waking
       it up (if there is no such process, fetchmail will notify you.  If  the
       --quit option appears last on the command line, fetchmail will kill the
       running daemon process and then quit. Otherwise, fetchmail  will	 first
       kill  a running daemon process and then continue running with the other
       options.

   Useful options for daemon mode
       The -L <filename> or --logfile <filename> option (keyword: set logfile)
       is  only	 effective  when  fetchmail is detached. Note that the logfile
       must exist BEFORE fetchmail is run, you can use	the  touch(1)  command
       with the filename as its sole argument to create it.
       This  option  allows  you  to redirect status messages into a specified
       logfile (follow the option with the  logfile  name).   The  logfile  is
       opened  for  append, so previous messages aren't deleted.  This is pri‐
       marily useful for debugging configurations. Note	 that  fetchmail  does
       not  detect  if the logfile is rotated, the logfile is only opened once
       when fetchmail starts. You need to restart fetchmail after rotating the
       logfile and before compressing it (if applicable).

       The --syslog option (keyword: set syslog) allows you to redirect status
       and error messages emitted to the syslog(3) system daemon if available.
       Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
       priorities LOG_ERR, LOG_ALERT or LOG_INFO.  This option is intended for
       logging status and error messages which indicate the status of the dae‐
       mon and the results while fetching mail from the server(s).  Error mes‐
       sages  for  command  line options and parsing the .fetchmailrc file are
       still written to stderr, or to the specified log file.  The  --nosyslog
       option  turns  off  use	of  syslog(3),	assuming it's turned on in the
       ~/.fetchmailrc file, or that the -L  or	--logfile  <file>  option  was
       used.

       The  -N or --nodetach option suppresses backgrounding and detachment of
       the daemon process from its  control  terminal.	 This  is  useful  for
       debugging  or  when fetchmail runs as the child of a supervisor process
       such as init(8) or Gerrit Pape's runit.	Note that this also causes the
       logfile option to be ignored (though perhaps it shouldn't).

       Note  that  while  running  in  daemon  mode polling a POP2 or IMAP2bis
       server, transient errors (such as DNS  failures	or  sendmail  delivery
       refusals) may force the fetchall option on for the duration of the next
       polling cycle.  This is a robustness feature.  It means that if a  mes‐
       sage is fetched (and thus marked seen by the mailserver) but not deliv‐
       ered locally due to some transient error, it will be re-fetched	during
       the  next  poll	cycle.	 (The IMAP logic doesn't delete messages until
       they're delivered, so this problem does not arise.)

       If you touch or change the ~/.fetchmailrc file while fetchmail is  run‐
       ning in daemon mode, this will be detected at the beginning of the next
       poll cycle.  When  a  changed  ~/.fetchmailrc  is  detected,  fetchmail
       rereads	it and restarts from scratch (using exec(2); no state informa‐
       tion is retained in the new instance).  Note also that if you break the
       ~/.fetchmailrc file's syntax, the new instance will softly and silently
       vanish away on startup.

ADMINISTRATIVE OPTIONS
       The --postmaster <name> option (keyword: set postmaster) specifies  the
       last-resort  username  to which multidrop mail is to be forwarded if no
       matching local recipient can be found. It is also used  as  destination
       of  undeliverable  mail	if  the	 'bouncemail' global option is off and
       additionally for spam-blocked mail if the 'bouncemail' global option is
       off  and	 the 'spambounce' global option is on. This option defaults to
       the user who invoked fetchmail.	If the invoking user is root, then the
       default of this option is the user 'postmaster'.	 Setting postmaster to
       the empty string causes such mail as described above to be discarded  -
       this  however  is  usually a bad idea.  See also the description of the
       'FETCHMAILUSER' environment variable in the ENVIRONMENT section below.

       The --nobounce behaves like the	"set  no  bouncemail"  global  option,
       which see.

       The --invisible option (keyword: set invisible) tries to make fetchmail
       invisible.  Normally, fetchmail behaves like any other MTA would --  it
       generates  a  Received header into each message describing its place in
       the chain of transmission, and tells the MTA it forwards	 to  that  the
       mail  came  from	 the  machine  fetchmail itself is running on.	If the
       invisible option is on, the Received header is suppressed and fetchmail
       tries  to  spoof	 the MTA it forwards to into thinking it came directly
       from the mailserver host.

       The --showdots option (keyword: set showdots) forces fetchmail to  show
       progress	 dots  even if the current tty is not stdout (for example log‐
       files).	Fetchmail shows the dots by default when run in nodetach  mode
       or when daemon mode is not enabled.

       By  specifying  the  --tracepolls  option, you can ask fetchmail to add
       information to the Received header on the form "polling {label} account
       {user}", where {label} is the account label (from the specified rcfile,
       normally ~/.fetchmailrc) and {user} is the username which  is  used  to
       log  on	to  the mail server. This header can be used to make filtering
       email where no useful header information is available and you want mail
       from  different	accounts  sorted into different mailboxes (this could,
       for example, occur if you have an account on the same server running  a
       mailing	list,  and are subscribed to the list using that account). The
       default is not adding any such header.  In .fetchmailrc, this is called
       'tracepolls'.

RETRIEVAL FAILURE MODES
       The protocols fetchmail uses to talk to mailservers are next to bullet‐
       proof.  In normal operation forwarding to port 25, no message  is  ever
       deleted	(or  even marked for deletion) on the host until the SMTP lis‐
       tener on the client side has acknowledged to fetchmail that the message
       has been either accepted for delivery or rejected due to a spam block.

       When forwarding to an MDA, however, there is more possibility of error.
       Some MDAs are 'safe' and reliably return a nonzero status on any deliv‐
       ery  error, even one due to temporary resource limits.  The maildrop(1)
       program is like this; so are most programs designed as  mail  transport
       agents,	such as sendmail(1), including the sendmail wrapper of Postfix
       and exim(1).  These programs give back a reliable positive acknowledge‐
       ment  and  can  be  used with the mda option with no risk of mail loss.
       Unsafe MDAs, though, may return 0 even on delivery  failure.   If  this
       happens, you will lose mail.

       The normal mode of fetchmail is to try to download only 'new' messages,
       leaving untouched  (and	undeleted)  messages  you  have	 already  read
       directly	 on  the server (or fetched with a previous fetchmail --keep).
       But you may find that messages you've already read on  the  server  are
       being  fetched  (and deleted) even when you don't specify --all.	 There
       are several reasons this can happen.

       One could be that you're using POP2.  The  POP2	protocol  includes  no
       representation  of  'new' or 'old' state in messages, so fetchmail must
       treat all messages as new all the time.	But POP2 is obsolete, so  this
       is unlikely.

       A  potential  POP3 problem might be servers that insert messages in the
       middle of mailboxes (some VMS implementations of mail are rumored to do
       this).	The  fetchmail	code assumes that new messages are appended to
       the end of the mailbox; when this is not true it	 may  treat  some  old
       messages	 as  new and vice versa.  Using UIDL whilst setting fastuidl 0
       might fix this, otherwise, consider switching to IMAP.

       Yet another POP3 problem is that if they can't make  tempfiles  in  the
       user's home directory, some POP3 servers will hand back an undocumented
       response that causes fetchmail to spuriously report "No mail".

       The IMAP code uses the presence or absence of the server flag \Seen  to
       decide  whether or not a message is new.	 This isn't the right thing to
       do, fetchmail should check the UIDVALIDITY and use UID, but it  doesn't
       do  that	 yet.  Under Unix, it counts on your IMAP server to notice the
       BSD-style Status flags set by mail user agents and set the  \Seen  flag
       from  them when appropriate.  All Unix IMAP servers we know of do this,
       though it's not specified by the IMAP RFCs.  If you ever	 trip  over  a
       server that doesn't, the symptom will be that messages you have already
       read on your host will look new to  the	server.	  In  this  (unlikely)
       case,  only  messages  you  fetched  with fetchmail --keep will be both
       undeleted and marked old.

       In ETRN and ODMR modes, fetchmail does not actually retrieve  messages;
       instead,	 it  asks the server's SMTP listener to start a queue flush to
       the client via SMTP.  Therefore it sends only undelivered messages.

SPAM FILTERING
       Many SMTP listeners allow administrators to set up 'spam filters'  that
       block  unsolicited  email  from specified domains.  A MAIL FROM or DATA
       line that triggers this feature will  elicit  an	 SMTP  response	 which
       (unfortunately) varies according to the listener.

       Newer versions of sendmail return an error code of 571.

       According  to RFC2821, the correct thing to return in this situation is
       550 "Requested action not taken: mailbox unavailable" (the  draft  adds
       "[E.g.,	mailbox	 not  found, no access, or command rejected for policy
       reasons].").

       Older versions of the exim MTA return 501 "Syntax error	in  parameters
       or arguments".

       The postfix MTA runs 554 as an antispam response.

       Zmailer	may  reject  code with a 500 response (followed by an enhanced
       status code that contains more information).

       Return codes which fetchmail treats as antispam responses and  discards
       the  message can be set with the 'antispam' option.  This is one of the
       only three circumstance under which fetchmail ever discards  mail  (the
       others  are the 552 and 553 errors described below, and the suppression
       of multidropped messages with a message-ID already seen).

       If fetchmail is fetching from an IMAP  server,  the  antispam  response
       will be detected and the message rejected immediately after the headers
       have been fetched, without reading the message body.  Thus,  you	 won't
       pay for downloading spam message bodies.

       By default, the list of antispam responses is empty.

       If  the spambounce global option is on, mail that is spam-blocked trig‐
       gers an RFC1892/RFC1894 bounce message informing the originator that we
       do not accept mail from it. See also BUGS.

SMTP/ESMTP ERROR HANDLING
       Besides	the  spam-blocking  described  above,  fetchmail takes special
       actions on the following SMTP/ESMTP error responses

       452 (insufficient system storage)
	    Leave the message in the server mailbox for later retrieval.

       552 (message exceeds fixed maximum message size)
	    Delete the message from the server.	 Send bounce-mail to the orig‐
	    inator.

       553 (invalid sending domain)
	    Delete  the	 message  from	the  server.   Don't  even try to send
	    bounce-mail to the originator.

       Other errors trigger bounce mail back to the originator. See also BUGS.

THE RUN CONTROL FILE
       The preferred way to set up fetchmail is to write a  .fetchmailrc  file
       in  your	 home directory (you may do this directly, with a text editor,
       or indirectly via fetchmailconf).  When there is a conflict between the
       command-line arguments and the arguments in this file, the command-line
       arguments take precedence.

       To protect the security of your passwords, your ~/.fetchmailrc may  not
       normally	 have more than 0700 (u=rwx,g=,o=) permissions; fetchmail will
       complain and exit otherwise (this check is suppressed when --version is
       on).

       You may read the .fetchmailrc file as a list of commands to be executed
       when fetchmail is called with no arguments.

   Run Control Syntax
       Comments begin with a '#' and extend through the end of the line.  Oth‐
       erwise the file consists of a series of server entries or global option
       statements in a free-format, token-oriented syntax.

       There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
       digit  sequences),  unquoted  strings,  and  quoted  strings.  A quoted
       string is bounded by double quotes  and	may  contain  whitespace  (and
       quoted  digits are treated as a string).	 Note that quoted strings will
       also contain line feed characters if they run across two or more lines,
       unless  you  use	 a  backslash  to join lines (see below).  An unquoted
       string is any  whitespace-delimited  token  that	 is  neither  numeric,
       string  quoted  nor  contains  the special characters ',', ';', ':', or
       '='.

       Any amount of whitespace separates tokens in  server  entries,  but  is
       otherwise  ignored.  You may use backslash escape sequences (\n for LF,
       \t for HT, \b for BS, \r for CR, \nnn for  decimal  (where  nnn	cannot
       start with a 0), \0ooo for octal, and \xhh for hex) to embed non-print‐
       able characters or string delimiters in strings.	 In quoted strings,  a
       backslash at the very end of a line will cause the backslash itself and
       the line feed (LF or NL, new line) character to be ignored, so that you
       can  wrap long strings. Without the backslash at the line end, the line
       feed character would become part of the string.

       Warning: while these resemble C-style escape sequences,	they  are  not
       the  same.  fetchmail only supports these eight styles. C supports more
       escape sequences that consist of backslash (\) and a single  character,
       but  does  not support decimal codes and does not require the leading 0
       in octal notation.  Example: fetchmail interprets \233 the same as \xE9
       (Latin  small  letter  e	 with  acute), where C would interpret \233 as
       octal 0233 = \x9B (CSI, control sequence introducer).

       Each server entry consists of one of the	 keywords  'poll'  or  'skip',
       followed	 by a server name, followed by server options, followed by any
       number of user (or username) descriptions, followed  by	user  options.
       Note:  the  most	 common	 cause	of syntax errors is mixing up user and
       server options or putting user options before the user descriptions.

       For backward compatibility, the word 'server' is a synonym for 'poll'.

       You can use the noise  keywords	'and',	'with',	 'has',	 'wants',  and
       'options'  anywhere  in	an entry to make it resemble English.  They're
       ignored, but but can make entries much easier to read at a glance.  The
       punctuation characters ':', ';' and ',' are also ignored.

   Poll vs. Skip
       The  'poll' verb tells fetchmail to query this host when it is run with
       no arguments.  The 'skip' verb tells fetchmail not to  poll  this  host
       unless  it  is  explicitly named on the command line.  (The 'skip' verb
       allows you to experiment with test entries safely,  or  easily  disable
       entries for hosts that are temporarily down.)

   Keyword/Option Summary
       Here are the legal options.  Keyword suffixes enclosed in square brack‐
       ets are optional.  Those corresponding to  short	 command-line  options
       are  followed  by  '-' and the appropriate option letter.  If option is
       only relevant to a single mode of operation, it is noted as 's' or  'm'
       for singledrop- or multidrop-mode, respectively.

       Here are the legal global options:

       Keyword		   Opt	 Mode	Function
       ────────────────────────────────────────────────────────────────────
       set daemon	   -d		Set  a background poll interval in
					seconds.
       set postmaster			Give the name of  the  last-resort
					mail recipient (default: user run‐
					ning  fetchmail,  "postmaster"	if
					run by the root user)
       set    bouncemail		Direct	error  mail  to the sender
					(default)
       set no bouncemail		Direct error  mail  to	the  local
					postmaster  (as	 per the 'postmas‐
					ter' global option above).
       set no spambounce		Do not	bounce	spam-blocked  mail
					(default).

       set    spambounce		Bounce	blocked	 spam-blocked mail
					(as  per   the	 'antispam'   user
					option) back to the destination as
					indicated  by	the   'bouncemail'
					global	option.	  Warning:  Do not
					use this to bounce  spam  back	to
					the  sender  -	most  spam is sent
					with false sender address and thus
					this	option	  hurts	  innocent
					bystanders.
       set logfile	   -L		Name of a file to append error and
					status messages to.
       set idfile	   -i		Name  of  the  file  to	 store UID
					lists in.
       set    syslog			Do  error  logging  through   sys‐
					log(3).
       set no syslog			Turn  off  error  logging  through
					syslog(3). (default)
       set properties			String value that  is  ignored	by
					fetchmail  (may	 be used by exten‐
					sion scripts).

       Here are the legal server options:

       Keyword		Opt   Mode   Function
       ─────────────────────────────────────────────────────────────────
       via			     Specify DNS  name	of  mailserver,
				     overriding poll name
       proto[col]	-p	     Specify  protocol	(case  insensi‐
				     tive):  POP2,  POP3,  IMAP,  APOP,
				     KPOP
       local[domains]	      m	     Specify  domain(s)	 to be regarded
				     as local
       port			     Specify TCP/IP service port (obso‐
				     lete, use 'service' instead).
       service		-P	     Specify  service  name  (a numeric
				     value is also allowed and	consid‐
				     ered a TCP/IP port number).
       auth[enticate]		     Set  authentication  type (default
				     'any')
       timeout		-t	     Server inactivity timeout in  sec‐
				     onds (default 300)
       envelope		-E    m	     Specify   envelope-address	 header
				     name
       no envelope	      m	     Disable   looking	 for   envelope
				     address
       qvirtual		-Q    m	     Qmail  virtual  domain  prefix  to
				     remove from user name
       aka		      m	     Specify  alternate	 DNS  names  of
				     mailserver
       interface	-I	     specify  IP interface(s) that must
				     be up  for	 server	 poll  to  take
				     place
       monitor		-M	     Specify  IP address to monitor for
				     activity
       plugin			     Specify command through  which  to
				     make server connections.
       plugout			     Specify  command  through which to
				     make listener connections.
       dns		      m	     Enable DNS	 lookup	 for  multidrop
				     (default)
       no dns		      m	     Disable DNS lookup for multidrop
       checkalias	      m	     Do	 comparison  by	 IP address for
				     multidrop

       no checkalias	      m	     Do comparison  by	name  for  mul‐
				     tidrop (default)
       uidl		-U	     Force   POP3  to  use  client-side
				     UIDLs (recommended)
       no uidl			     Turn off POP3 use	of  client-side
				     UIDLs (default)
       interval			     Only  check this site every N poll
				     cycles; N is a numeric argument.
       tracepolls		     Add poll  tracing	information  to
				     the Received header
       principal		     Set  Kerberos principal (only use‐
				     ful with IMAP and kerberos)
       esmtpname		     Set name for  RFC2554  authentica‐
				     tion to the ESMTP server.
       esmtppassword		     Set password for RFC2554 authenti‐
				     cation to the ESMTP server.

       Here are the legal user descriptions and options:

       Keyword		  Opt	Mode   Function
       ───────────────────────────────────────────────────────────────────
       user[name]	  -u	       This is the user	 description  and
				       must   come   first  after  server
				       description  and	 after	 possible
				       server  options,	 and  before user
				       options.
				       It sets the remote user name if by
				       itself  or followed by 'there', or
				       the local user name if followed by
				       'here'.
       is			       Connect	 local	and  remote  user
				       names
       to			       Connect	local  and  remote   user
				       names
       pass[word]		       Specify remote account password
       ssl			       Connect	to server over the speci‐
				       fied  base  protocol   using   SSL
				       encryption
       sslcert			       Specify	file for client side pub‐
				       lic SSL certificate
       sslkey			       Specify file for client side  pri‐
				       vate SSL key
       sslproto			       Force ssl protocol for connection
       folder		  -r	       Specify remote folder to query
       smtphost		  -S	       Specify smtp host(s) to forward to
       fetchdomains		m      Specify	domains	 for  which  mail
				       should be fetched
       smtpaddress	  -D	       Specify the domain to  be  put  in
				       RCPT TO lines
       smtpname			       Specify	the user and domain to be
				       put in RCPT TO lines
       antispam		  -Z	       Specify	what  SMTP  returns   are
				       interpreted as spam-policy blocks
       mda		  -m	       Specify MDA for local delivery
       bsmtp		  -o	       Specify BSMTP batch file to append
				       to
       preconnect		       Command to be executed before each
				       connection
       postconnect		       Command	to be executed after each
				       connection
       keep		  -k	       Don't delete  seen  messages  from
				       server  (for  POP3, uidl is recom‐
				       mended)
       flush		  -F	       Flush  all  seen	 messages  before
				       querying (DANGEROUS)

       limitflush		       Flush   all   oversized	 messages
				       before querying
       fetchall		  -a	       Fetch all messages whether seen or
				       not
       rewrite			       Rewrite	destination addresses for
				       reply (default)
       stripcr			       Strip carriage returns  from  ends
				       of lines
       forcecr			       Force  carriage returns at ends of
				       lines
       pass8bits		       Force BODY=8BITMIME to ESMTP  lis‐
				       tener
       dropstatus		       Strip  Status and X-Mozilla-Status
				       lines out of incoming mail
       dropdelivered		       Strip Delivered-To  lines  out  of
				       incoming mail
       mimedecode		       Convert	quoted-printable to 8-bit
				       in MIME messages
       idle			       Idle  waiting  for  new	 messages
				       after each poll (IMAP only)
       no keep		  -K	       Delete  seen  messages from server
				       (default)
       no flush			       Don't  flush  all  seen	 messages
				       before querying (default)
       no fetchall		       Retrieve	   only	   new	 messages
				       (default)
       no rewrite		       Don't rewrite headers
       no stripcr		       Don't   strip   carriage	  returns
				       (default)
       no forcecr		       Don't  force  carriage  returns at
				       EOL (default)
       no pass8bits		       Don't force BODY=8BITMIME to ESMTP
				       listener (default)
       no dropstatus		       Don't	drop	Status	  headers
				       (default)
       no dropdelivered		       Don't  drop  Delivered-To  headers
				       (default)
       no mimedecode		       Don't  convert quoted-printable to
				       8-bit in MIME messages (default)
       no idle			       Don't idle waiting  for	new  mes‐
				       sages after each poll (IMAP only)
       limit		  -l	       Set message size limit
       warnings		  -w	       Set message size warning interval
       batchlimit	  -b	       Max  # messages to forward in sin‐
				       gle connect
       fetchlimit	  -B	       Max # messages to fetch in  single
				       connect
       fetchsizelimit		       Max  #  message	sizes to fetch in
				       single transaction
       fastuidl			       Use binary search for first unseen
				       message (POP3 only)
       expunge		  -e	       Perform	an  expunge  on every #th
				       message (IMAP and POP3 only)
       properties		       String value is ignored by  fetch‐
				       mail  (may  be  used  by extension
				       scripts)

       All user options must begin with a user description (user  or  username
       option) and follow all server descriptions and options.

       In  the	.fetchmailrc  file, the 'envelope' string argument may be pre‐
       ceded by a whitespace-separated number.	This number, if specified,  is
       the  number  of	such  headers  to skip over (that is, an argument of 1
       selects the second header of the given type).  This is sometime	useful
       for  ignoring bogus envelope headers created by an ISP's local delivery
       agent or	 internal  forwards  (through  mail  inspection	 systems,  for
       instance).

   Keywords Not Corresponding To Option Switches
       The  'folder' and 'smtphost' options (unlike their command-line equiva‐
       lents) can take a space- or comma-separated  list  of  names  following
       them.

       All  options  correspond	 to the obvious command-line arguments, except
       the following: 'via', 'interval', 'aka', 'is',  'to',  'dns'/'no	 dns',
       'checkalias'/'no	 checkalias', 'password', 'preconnect', 'postconnect',
       'localdomains',	 'stripcr'/'no	 stripcr',   'forcecr'/'no   forcecr',
       'pass8bits'/'no	 pass8bits'  'dropstatus/no  dropstatus',  'dropdeliv‐
       ered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle', and  'no
       envelope'.

       The 'via' option is for if you want to have more than one configuration
       pointing at the same site.  If it is present, the string argument  will
       be  taken as the actual DNS name of the mailserver host to query.  This
       will override the argument of poll, which can then simply be a distinct
       label  for  the	configuration (e.g. what you would give on the command
       line to explicitly query this host).

       The 'interval' option (which takes a numeric argument)  allows  you  to
       poll a server less frequently than the basic poll interval.  If you say
       'interval N' the server this option is attached to will only be queried
       every N poll intervals.

   Singledrop vs. Multidrop options
       Please  ensure  you  read  the section titled THE USE AND ABUSE OF MUL‐
       TIDROP MAILBOXES if you intend to use multidrop mode.

       The 'is' or  'to'  keywords  associate  the  following  local  (client)
       name(s)	(or  server-name  to client-name mappings separated by =) with
       the mailserver user name in the entry.  If an is/to list has '*' as its
       last  name,  unrecognized  names	 are  simply passed through. Note that
       until fetchmail version 6.3.4 inclusively, these lists could only  con‐
       tain  local  parts of user names (fetchmail would only look at the part
       before the @ sign). fetchmail versions 6.3.5  and  newer	 support  full
       addresses on the left hand side of these mappings, and they take prece‐
       dence over any 'localdomains', 'aka', 'via' or similar mappings.

       A single local name can be used to support redirecting your  mail  when
       your  username on the client machine is different from your name on the
       mailserver.  When there is only a single local name, mail is  forwarded
       to  that	 local	username regardless of the message's Received, To, Cc,
       and Bcc headers.	 In this case, fetchmail never does DNS lookups.

       When there is more than one local name  (or  name  mapping),  fetchmail
       looks  at  the  envelope	 header,  if  configured, and otherwise at the
       Received, To, Cc, and Bcc headers of retrieved mail (this is 'multidrop
       mode').	 It  looks  for	 addresses with hostname parts that match your
       poll name or your 'via', 'aka' or 'localdomains' options,  and  usually
       also  for  hostname  parts  which  DNS  tells  it  are  aliases	of the
       mailserver.  See the discussion of 'dns', 'checkalias', 'localdomains',
       and 'aka' for details on how matching addresses are handled.

       If  fetchmail  cannot  match  any  mailserver  usernames or localdomain
       addresses, the mail will be bounced.  Normally it will  be  bounced  to
       the sender, but if the 'bouncemail' global option is off, the mail will
       go to the local	postmaster  instead.   (see  the  'postmaster'	global
       option). See also BUGS.

       The  'dns'  option  (normally  on) controls the way addresses from mul‐
       tidrop mailboxes are checked.  On, it enables logic to check each  host
       address	that  does not match an 'aka' or 'localdomains' declaration by
       looking it up with DNS.	 When  a  mailserver  username	is  recognized
       attached to a matching hostname part, its local mapping is added to the
       list of local recipients.

       The 'checkalias' option (normally off) extends the lookups performed by
       the  'dns'  keyword  in	multidrop  mode,  providing a way to cope with
       remote MTAs that identify themselves using their canonical name,	 while
       they're polled using an alias.  When such a server is polled, checks to
       extract the envelope address fail, and fetchmail	 reverts  to  delivery
       using   the   To/Cc/Bcc	 headers   (See	 below	'Header	 vs.  Envelope
       addresses').  Specifying this option instructs  fetchmail  to  retrieve
       all  the	 IP  addresses associated with both the poll name and the name
       used by the remote MTA and to do a  comparison  of  the	IP  addresses.
       This  comes  in	handy  in situations where the remote server undergoes
       frequent canonical name changes, that would otherwise require modifica‐
       tions  to the rcfile.  'checkalias' has no effect if 'no dns' is speci‐
       fied in the rcfile.

       The 'aka' option is for use with multidrop mailboxes.  It allows you to
       pre-declare  a  list of DNS aliases for a server.  This is an optimiza‐
       tion hack that allows you to trade space for  speed.   When  fetchmail,
       while  processing  a multidrop mailbox, grovels through message headers
       looking for names of the mailserver, pre-declaring common ones can save
       it  from	 having	 to do DNS lookups.  Note: the names you give as argu‐
       ments to 'aka' are matched as suffixes -- if  you  specify  (say)  'aka
       netaxs.com',  this  will	 match not just a hostname netaxs.com, but any
       hostname that ends with '.netaxs.com'; such  as	(say)  pop3.netaxs.com
       and mail.netaxs.com.

       The 'localdomains' option allows you to declare a list of domains which
       fetchmail should consider local.	 When  fetchmail  is  parsing  address
       lines in multidrop modes, and a trailing segment of a host name matches
       a declared local domain, that address is passed through to the listener
       or MDA unaltered (local-name mappings are not applied).

       If you are using 'localdomains', you may also need to specify 'no enve‐
       lope', which disables fetchmail's normal attempt to deduce an  envelope
       address	from  the  Received  line  or X-Envelope-To header or whatever
       header has been previously set by 'envelope'.  If you set 'no envelope'
       in the defaults entry it is possible to undo that in individual entries
       by using 'envelope <string>'.  As a special case, 'envelope "Received"'
       restores the default parsing of Received lines.

       The  password  option requires a string argument, which is the password
       to be used with the entry's server.

       The 'preconnect' keyword allows you to specify a shell  command	to  be
       executed	 just before each time fetchmail establishes a mailserver con‐
       nection.	 This may be useful if you are attempting to set up secure POP
       connections  with  the aid of ssh(1).  If the command returns a nonzero
       status, the poll of that mailserver will be aborted.

       Similarly, the 'postconnect' keyword similarly allows you to specify  a
       shell  command to be executed just after each time a mailserver connec‐
       tion is taken down.

       The 'forcecr' option controls whether lines terminated by LF  only  are
       given  CRLF  termination	 before	 forwarding.  Strictly speaking RFC821
       requires this, but few MTAs enforce the requirement it so  this	option
       is  normally  off  (only	 one such MTA, qmail, is in significant use at
       time of writing).

       The 'stripcr' option controls whether carriage returns are stripped out
       of retrieved mail before it is forwarded.  It is normally not necessary
       to set this, because it defaults to 'on' (CR  stripping	enabled)  when
       there  is  an  MDA declared but 'off' (CR stripping disabled) when for‐
       warding is via SMTP.  If 'stripcr' and 'forcecr' are both on, 'stripcr'
       will override.

       The 'pass8bits' option exists to cope with Microsoft mail programs that
       stupidly slap a "Content-Transfer-Encoding: 7bit" on everything.	  With
       this  option  off  (the	default)  and such a header present, fetchmail
       declares BODY=7BIT to an ESMTP-capable listener; this  causes  problems
       for  messages  actually	using 8-bit ISO or KOI-8 character sets, which
       will be garbled by having the high bits of all characters stripped.  If
       'pass8bits'  is on, fetchmail is forced to declare BODY=8BITMIME to any
       ESMTP-capable listener.	If the listener is  8-bit-clean	 (as  all  the
       major ones now are) the right thing will probably result.

       The 'dropstatus' option controls whether nonempty Status and X-Mozilla-
       Status lines are retained in fetched mail (the default)	or  discarded.
       Retaining  them	allows	your  MUA  to  see what messages (if any) were
       marked seen on the server.  On the other hand, it can confuse some new-
       mail notifiers, which assume that anything with a Status line in it has
       been seen.  (Note: the empty Status lines inserted by  some  buggy  POP
       servers are unconditionally discarded.)

       The  'dropdelivered'  option controls whether Delivered-To headers will
       be kept in fetched mail (the default) or discarded. These  headers  are
       added by Qmail and Postfix mailservers in order to avoid mail loops but
       may get in your way if you try to "mirror" a mailserver within the same
       domain. Use with caution.

       The  'mimedecode'  option  controls  whether  MIME  messages  using the
       quoted-printable encoding are automatically converted into  pure	 8-bit
       data.  If you are delivering mail to an ESMTP-capable, 8-bit-clean lis‐
       tener (that includes all of the major MTAs like	sendmail),  then  this
       will  automatically  convert  quoted-printable message headers and data
       into 8-bit data, making it easier to understand when reading  mail.  If
       your  e-mail  programs  know  how to deal with MIME messages, then this
       option is not needed.  The mimedecode option is off by default, because
       doing  RFC2047 conversion on headers throws away character-set informa‐
       tion and can lead to bad results if the encoding of the headers differs
       from the body encoding.

       The  'idle'  option is intended to be used with IMAP servers supporting
       the RFC2177 IDLE command extension, but does not strictly  require  it.
       If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
       will be issued at the end of each poll.	This will tell the IMAP server
       to  hold	 the  connection  open	and notify the client when new mail is
       available.  If IDLE is not supported, fetchmail	will  simulate	it  by
       periodically  issuing NOOP. If you need to poll a link frequently, IDLE
       can save bandwidth by  eliminating  TCP/IP  connects  and  LOGIN/LOGOUT
       sequences. On the other hand, an IDLE connection will eat almost all of
       your fetchmail's time, because it will never drop  the  connection  and
       allow  other  polls  to occur unless the server times out the IDLE.  It
       also doesn't work with multiple folders; only  the  first  folder  will
       ever be polled.

       The  'properties'  option is an extension mechanism.  It takes a string
       argument, which is ignored by fetchmail itself.	 The  string  argument
       may  be	used  to  store	 configuration	information  for scripts which
       require it.  In particular, the output of  '--configdump'  option  will
       make  properties	 associated  with  a user entry readily available to a
       Python script.

   Miscellaneous Run Control Options
       The words 'here' and 'there'  have  useful  English-like	 significance.
       Normally	 'user	eric  is esr' would mean that mail for the remote user
       'eric' is to be delivered to 'esr', but you can make  this  clearer  by
       saying 'user eric there is esr here', or reverse it by saying 'user esr
       here is eric there'

       Legal protocol identifiers for use with the 'protocol' keyword are:

	   auto (or AUTO) (legacy, to be removed from future release)
	   pop2 (or POP2) (legacy, to be removed from future release)
	   pop3 (or POP3)
	   sdps (or SDPS)
	   imap (or IMAP)
	   apop (or APOP)
	   kpop (or KPOP)

       Legal authentication types are  'any',  'password',  'kerberos',	 'ker‐
       beros_v4',  'kerberos_v5'  and 'gssapi', 'cram-md5', 'otp', 'msn' (only
       for POP3), 'ntlm', 'ssh', 'external' (only IMAP).  The 'password'  type
       specifies  authentication  by  normal  transmission  of a password (the
       password may be plain text or subject to	 protocol-specific  encryption
       as  in  CRAM-MD5);  'kerberos' tells fetchmail to try to get a Kerberos
       ticket at the start of each query instead, and send an arbitrary string
       as the password; and 'gssapi' tells fetchmail to use GSSAPI authentica‐
       tion.  See the description of the 'auth' keyword for more.

       Specifying 'kpop' sets POP3 protocol over port 1109  with  Kerberos  V4
       authentication.	These defaults may be overridden by later options.

       There  are  some	 global option statements: 'set logfile' followed by a
       string sets the same global specified  by  --logfile.   A  command-line
       --logfile option will override this. Note that --logfile is only effec‐
       tive if fetchmail detaches itself from the  terminal  and  the  logfile
       already	exists	before	fetchmail is run.  Also, 'set daemon' sets the
       poll interval as --daemon does.	This can be overridden by  a  command-
       line  --daemon  option;	in  particular --daemon 0 can be used to force
       foreground operation. The 'set postmaster' statement sets  the  address
       to  which  multidrop  mail  defaults  if	 there	are  no local matches.
       Finally, 'set syslog' sends log messages to syslogd(8).

DEBUGGING FETCHMAIL
   Fetchmail crashing
       There are various ways in that fetchmail may "crash", i. e. stop opera‐
       tion  suddenly  and  unexpectedly. A "crash" usually refers to an error
       condition that the software did not  handle  by	itself.	 A  well-known
       failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
       just "segfault" for short. These can be caused by hardware or by	 soft‐
       ware  problems.	Software-induced  segfaults  can usually be reproduced
       easily and in the same place, whereas hardware-induced segfaults can go
       away  if	 the computer is rebooted, or powered off for a few hours, and
       can happen in random locations even if you use the  software  the  same
       way.

       For  solving  hardware-induced segfaults, find the faulty component and
       repair or replace it.  <http://www.bitwizard.nl/sig11/>	may  help  you
       with details.

       For  solving  software-induced  segfaults,  the	developers  may need a
       "stack backtrace".

   Enabling fetchmail core dumps
       By default, fetchmail suppresses core  dumps  as	 these	might  contain
       passwords  and  other  sensitive	 information.  For debugging fetchmail
       crashes, obtaining a "stack backtrace" from a core dump	is  often  the
       quickest	 way  to solve the problem, and when posting your problem on a
       mailing list, the developers may ask you for a "backtrace".

       1. To get useful backtraces, fetchmail needs to	be  installed  without
       getting	stripped  of  its  compilation	symbols.   Unfortunately, most
       binary packages that are installed are stripped, and  core  files  from
       symbol-stripped	programs  are  worthless. So you may need to recompile
       fetchmail. On many systems, you can type

	       file `which fetchmail`

       to find out if fetchmail was  symbol-stripped  or  not.	If  yours  was
       unstripped,  fine,  proceed,  if it was stripped, you need to recompile
       the source code first. You do not usually need to install fetchmail  in
       order to debug it.

       2.  The	shell  environment  that starts fetchmail needs to enable core
       dumps. The key is the "maximum core (file) size" that  can  usually  be
       configured with a tool named "limit" or "ulimit". See the documentation
       for your shell for details. In the  popular  bash  shell,  "ulimit  -Sc
       unlimited" will allow the core dump.

       3.  You	need  to tell fetchmail, too, to allow core dumps. To do this,
       run fetchmail with the -d0 -v options.  It is often easier to also  add
       --nosyslog -N as well.

       Finally,	 you need to reproduce the crash. You can just start fetchmail
       from the directory where you compiled it by typing ./fetchmail, so  the
       complete	 command line will start with ./fetchmail -Nvd0 --nosyslog and
       perhaps list your other options.

       After the crash, run your debugger to obtain the core dump.  The debug‐
       ger  will  often	 be GNU GDB, you can then type (adjust paths as neces‐
       sary) gdb ./fetchmail fetchmail.core and then, after GDB has started up
       and  read  all  its files, type backtrace full, save the output (copy &
       paste will do, the backtrace will be read by a  human)  and  then  type
       quit  to leave gdb.  Note: on some systems, the core files have differ‐
       ent names, they might contain a number instead of the program name,  or
       number and name, but it will usually have "core" as part of their name.

INTERACTION WITH RFC 822
       When  trying  to determine the originating address of a message, fetch‐
       mail looks through headers in the following order:

	       Return-Path:
	       Resent-Sender: (ignored if it doesn't contain an @ or !)
	       Sender: (ignored if it doesn't contain an @ or !)
	       Resent-From:
	       From:
	       Reply-To:
	       Apparently-From:

       The originating address is used for logging, and to set the  MAIL  FROM
       address when forwarding to SMTP.	 This order is intended to cope grace‐
       fully with receiving mailing  list  messages  in	 multidrop  mode.  The
       intent  is  that	 if  a local address doesn't exist, the bounce message
       won't be returned blindly to the author or  to  the  list  itself,  but
       rather to the list manager (which is less annoying).

       In multidrop mode, destination headers are processed as follows: First,
       fetchmail looks for the header specified by the	'envelope'  option  in
       order  to  determine  the  local	 recipient  address.  If  the  mail is
       addressed to more than one recipient, the Received line	won't  contain
       any information regarding recipient addresses.

       Then  fetchmail	looks  for the Resent-To:, Resent-Cc:, and Resent-Bcc:
       lines.  If they exist, they should contain  the	final  recipients  and
       have  precedence over their To:/Cc:/Bcc: counterparts.  If the Resent-*
       lines don't exist, the To:, Cc:,	 Bcc:  and  Apparently-To:  lines  are
       looked  for.  (The  presence of a Resent-To: is taken to imply that the
       person referred by the To: address has already  received	 the  original
       copy of the mail.)

CONFIGURATION EXAMPLES
       Note  that  although  there are password declarations in a good many of
       the examples below, this is mainly for illustrative purposes.  We  rec‐
       ommend stashing account/password pairs in your $HOME/.netrc file, where
       they can be used not just by fetchmail but by  ftp(1)  and  other  pro‐
       grams.

       Basic format is:

	 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD

       Example:

	 poll pop.provider.net protocol pop3 username "jsmith" password "secret1" ssl

       Or, using some abbreviations:

	 poll pop.provider.net proto pop3 user "jsmith" password "secret1"

       Multiple servers may be listed:

	 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
	 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"

       Here's  a  version  of  those  two  with more whitespace and some noise
       words:

	 poll pop.provider.net proto pop3
	     user "jsmith", with password secret1, is "jsmith" here;
	 poll other.provider.net proto pop2:
	     user "John.Smith", with password "My^Hat", is "John.Smith" here;

       This version is much easier to read and doesn't cost significantly more
       (parsing is done only once, at startup time).

       If  you	need  to include whitespace in a parameter string or start the
       latter with a number, enclose the string in double quotes.  Thus:

	 poll mail.provider.net with proto pop3:
	       user "jsmith" there has password "4u but u can't krak this"
			   is jws here and wants mda "/bin/mail"

       You may have an	initial	 server	 description  headed  by  the  keyword
       'defaults'  instead  of	'poll'	followed  by a name.  Such a record is
       interpreted as defaults for all queries to use. It may  be  overwritten
       by individual server descriptions.  So, you could write:

	 defaults proto pop3
	       user "jsmith"
	 poll pop.provider.net
	       pass "secret1"
	 poll mail.provider.net
	       user "jjsmith" there has password "secret2"

       It's  possible  to  specify  more than one user per server.  The 'user'
       keyword leads off a user description, and every user specification in a
       multi-user entry must include it.  Here's an example:

	 poll pop.provider.net proto pop3 port 3111
	       user "jsmith" with pass "secret1" is "smith" here
	       user jones with pass "secret2" is "jjones" here keep

       This  associates	 the  local username 'smith' with the pop.provider.net
       username	 'jsmith'  and	the   local   username	 'jjones'   with   the
       pop.provider.net	 username  'jones'.   Mail  for 'jones' is kept on the
       server after download.

       Here's what a simple retrieval configuration for	 a  multidrop  mailbox
       looks like:

	 poll pop.provider.net:
	       user maildrop with pass secret1 to golux 'hurkle'='happy' snark here

       This  says  that	 the  mailbox of account 'maildrop' on the server is a
       multidrop box, and that messages in it should be parsed for the	server
       user  names  'golux', 'hurkle', and 'snark'.  It further specifies that
       'golux' and 'snark' have the same name on the client as on the  server,
       but  mail  for  server user 'hurkle' should be delivered to client user
       'happy'.

       Note  that  fetchmail,  until  version  6.3.4,  did  NOT	  allow	  full
       user@domain  specifications  here,  these  would never match. Fetchmail
       6.3.5 and newer support user@domain  specifications  on	the  left-hand
       side of a user mapping.

       Here's an example of another kind of multidrop connection:

	 poll pop.provider.net localdomains loonytoons.org toons.org
	     envelope X-Envelope-To
	       user maildrop with pass secret1 to * here

       This  also says that the mailbox of account 'maildrop' on the server is
       a multidrop box.	 It tells fetchmail that any  address  in  the	loony‐
       toons.org  or  toons.org	 domains  (including sub-domain addresses like
       'joe@daffy.loonytoons.org') should be passed through to the local  SMTP
       listener	 without  modification.	  Be  careful  of mail loops if you do
       this!

       Here's an example configuration using ssh and the plugin	 option.   The
       queries	are  made  directly  on the stdin and stdout of imapd via ssh.
       Note that in this setup, IMAP authentication can be skipped.

       poll mailhost.net with proto imap:
	       plugin "ssh %h /usr/sbin/imapd" auth ssh;
		       user esr is esr here

THE USE AND ABUSE OF MULTIDROP MAILBOXES
       Use the multiple-local-recipients feature with caution -- it can	 bite.
       All multidrop features are ineffective in ETRN and ODMR modes.

       Also,  note  that  in multidrop mode duplicate mails are suppressed.  A
       piece of mail is considered duplicate if it has the same message-ID  as
       the  message  immediately  preceding and more than one addressee.  Such
       runs of messages may be generated when copies of a message addressed to
       multiple users are delivered to a multidrop box.

   Header vs. Envelope addresses
       The  fundamental problem is that by having your mailserver toss several
       peoples' mail in a single maildrop box, you may have thrown away poten‐
       tially  vital  information  about  who  each piece of mail was actually
       addressed  to  (the  'envelope  address',  as  opposed  to  the	header
       addresses in the RFC822 To/Cc headers - the Bcc is not available at the
       receiving end).	This 'envelope address' is the	address	 you  need  in
       order to reroute mail properly.

       Sometimes fetchmail can deduce the envelope address.  If the mailserver
       MTA is sendmail and the item of mail had just one  recipient,  the  MTA
       will  have  written a 'by/for' clause that gives the envelope addressee
       into its Received header. But this  doesn't  work  reliably  for	 other
       MTAs,  nor  if there is more than one recipient.	 By default, fetchmail
       looks for envelope addresses in	these  lines;  you  can	 restore  this
       default with -E "Received" or 'envelope Received'.

       As a better alternative, some SMTP listeners and/or mail servers insert
       a header in each message containing a copy of the  envelope  addresses.
       This  header  (when it exists) is often 'X-Original-To', 'Delivered-To'
       or 'X-Envelope-To'.  Fetchmail's assumption about this can  be  changed
       with the -E or 'envelope' option.  Note that writing an envelope header
       of this kind exposes the	 names	of  recipients	(including  blind-copy
       recipients)  to	all  receivers	of  the messages, so the upstream must
       store one copy of the message per recipient to avoid becoming a privacy
       problem.

       Postfix,	 since version 2.0, writes an X-Original-To: header which con‐
       tains a copy of the envelope as it was received.

       Qmail and Postfix generally write a 'Delivered-To' header upon deliver‐
       ing  the	 message  to  the  mail	 spool and use it to avoid mail loops.
       Qmail virtual domains however will prefix the user name with  a	string
       that  normally matches the user's domain. To remove this prefix you can
       use the -Q or 'qvirtual' option.

       Sometimes, unfortunately, neither of these methods works.  That is  the
       point  when you should contact your ISP and ask them to provide such an
       envelope header, and you should not use multidrop  in  this  situation.
       When  they  all fail, fetchmail must fall back on the contents of To/Cc
       headers (Bcc headers are not available - see below) to try to determine
       recipient addressees -- and these are unreliable.  In particular, mail‐
       ing-list software often ships mail with only the list broadcast address
       in the To header.

       Note that a future version of fetchmail may remove To/Cc parsing!

       When fetchmail cannot deduce a recipient address that is local, and the
       intended recipient address was anyone other than	 fetchmail's  invoking
       user,  mail  will  get  lost.  This is what makes the multidrop feature
       risky without proper envelope information.

       A related problem is that when you blind-copy a mail message,  the  Bcc
       information  is carried only as envelope address (it's removed from the
       headers by the sending mail server, so fetchmail can  see  it  only  if
       there  is  an  X-0elope-To header).  Thus, blind-copying to someone who
       gets mail over a fetchmail multidrop link  will	fail  unless  the  the
       mailserver  host routinely writes X-Envelope-To or an equivalent header
       into messages in your maildrop.

       In conclusion, mailing lists and Bcc'd mail can only work if the server
       you're  fetching	 from (1) stores one copy of the message per recipient
       in your domain and (2) records the envelope information	in  a  special
       header (X-Original-To, Delivered-To, X-Envelope-To).

   Good Ways To Use Multidrop Mailboxes
       Multiple	 local names can be used to administer a mailing list from the
       client side of a fetchmail collection.  Suppose your name is 'esr', and
       you  want  to  both  pick  up your own mail and maintain a mailing list
       called (say) "fetchmail-friends", and you want to keep the  alias  list
       on your client machine.

       On  your	 server,  you can alias 'fetchmail-friends' to 'esr'; then, in
       your .fetchmailrc, declare 'to esr fetchmail-friends here'.  Then, when
       mail including 'fetchmail-friends' as a local address gets fetched, the
       list name will be appended to the list of recipients your SMTP listener
       sees.   Therefore  it will undergo alias expansion locally.  Be sure to
       include 'esr' in the local alias	 expansion  of	fetchmail-friends,  or
       you'll  never  see  mail sent only to the list.	Also be sure that your
       listener has the "me-too"  option  set  (sendmail's  -oXm  command-line
       option or OXm declaration) so your name isn't removed from alias expan‐
       sions in messages you send.

       This trick is not without its problems, however.	 You'll begin  to  see
       this  when  a message comes in that is addressed only to a mailing list
       you do not have declared as a local name.  Each such message will  fea‐
       ture  an 'X-Fetchmail-Warning' header which is generated because fetch‐
       mail cannot find a valid local name in the recipient  addresses.	  Such
       messages	 default  (as  was described above) to being sent to the local
       user running fetchmail, but the program has no way to know that	that's
       actually the right thing.

   Bad Ways To Abuse Multidrop Mailboxes
       Multidrop mailboxes and fetchmail serving multiple users in daemon mode
       do not mix.  The problem, again, is mail from mailing lists, which typ‐
       ically  does  not  have an individual recipient address on it.	Unless
       fetchmail can deduce an envelope address, such mail will only go to the
       account	running	 fetchmail  (probably root).  Also, blind-copied users
       are very likely never to see their mail at all.

       If you're tempted to use fetchmail to retrieve mail for multiple	 users
       from  a	single	mail drop via POP or IMAP, think again (and reread the
       section on header and envelope addresses above).	 It would  be  smarter
       to  just let the mail sit in the mailserver's queue and use fetchmail's
       ETRN or ODMR modes to trigger SMTP sends periodically (of course,  this
       means  you  have	 to  poll more frequently than the mailserver's expiry
       period).	 If you can't arrange this, try setting up a UUCP feed.

       If you absolutely must use multidrop for this purpose, make  sure  your
       mailserver  writes  an  envelope-address header that fetchmail can see.
       Otherwise you will lose mail and it will come back to haunt you.

   Speeding Up Multidrop Checking
       Normally, when multiple users are declared fetchmail extracts recipient
       addresses  as described above and checks each host part with DNS to see
       if it's an alias of the mailserver.  If so, the name mappings described
       in  the	"to ... here" declaration are done and the mail locally deliv‐
       ered.

       This is a convenient but also slow method.  To speed it up, pre-declare
       mailserver aliases with 'aka'; these are checked before DNS lookups are
       done.  If you're certain your aka list contains all DNS aliases of  the
       mailserver (and all MX names pointing at it - note this may change in a
       future version) you can	declare	 'no  dns'  to	suppress  DNS  lookups
       entirely and only match against the aka list.

SOCKS
       Support	for socks4/5 is a compile time configuration option. Once com‐
       piled in, fetchmail will always use the socks libraries and  configura‐
       tion  on your system, there are no run-time switches in fetchmail - but
       you can still configure SOCKS: you can specify which  SOCKS  configura‐
       tion file is used in the SOCKS_CONF environment variable.

       For  instance,  if  you wanted to bypass the SOCKS proxy altogether and
       have   fetchmail	  connect    directly,	  you	 could	  just	  pass
       SOCKS_CONF=/dev/null  in	 the  environment, for example (add your usual
       command line options - if any - to the end of this line):

       env SOCKS_CONF=/dev/null fetchmail

EXIT CODES
       To facilitate the use of fetchmail in  shell  scripts,  an  exit status
       code  is returned to give an indication of what occurred during a given
       connection.

       The exit codes returned by fetchmail are as follows:

       0      One or more messages were successfully retrieved (or, if the  -c
	      option was selected, were found waiting but not retrieved).

       1      There  was no mail awaiting retrieval.  (There may have been old
	      mail still on the server but not selected for retrieval.)

       2      An error was encountered when attempting to  open	 a  socket  to
	      retrieve	mail.  If you don't know what a socket is, don't worry
	      about it -- just treat this as an 'unrecoverable	error'.	  This
	      error  can  also be because a protocol fetchmail wants to use is
	      not listed in /etc/services.

       3      The user authentication step failed.  This usually means that  a
	      bad user-id, password, or APOP id was specified.	Or it may mean
	      that you tried to run fetchmail under circumstances where it did
	      not  have	 standard  input  attached to a terminal and could not
	      prompt for a missing password.

       4      Some sort of fatal protocol error was detected.

       5      There was a syntax error in the arguments to fetchmail.

       6      The run control file had bad permissions.

       7      There was an error condition reported by the server.   Can  also
	      fire if fetchmail timed out while waiting for the server.

       8      Client-side  exclusion error.  This means fetchmail either found
	      another copy of itself already running, or failed in such a  way
	      that it isn't sure whether another copy is running.

       9      The user authentication step failed because the server responded
	      "lock busy".  Try again after a brief pause!  This error is  not
	      implemented  for	all  protocols,	 nor  for all servers.	If not
	      implemented for your server, "3" will be returned	 instead,  see
	      above.  May be returned when talking to qpopper or other servers
	      that can respond with "lock busy" or some similar text  contain‐
	      ing the word "lock".

       10     The fetchmail run failed while trying to do an SMTP port open or
	      transaction.

       11     Fatal DNS error.	Fetchmail encountered an error while  perform‐
	      ing a DNS lookup at startup and could not proceed.

       12     BSMTP batch file could not be opened.

       13     Poll terminated by a fetch limit (see the --fetchlimit option).

       14     Server busy indication.

       23     Internal error.  You should see a message on standard error with
	      details.

       24 - 26, 28, 29
	      These are internal codes and should not appear externally.

       When fetchmail queries more than one host, return status is  0  if  any
       query  successfully retrieved mail. Otherwise the returned error status
       is that of the last host queried.

FILES
       ~/.fetchmailrc
	    default run control file

       ~/.fetchids
	    default location of file recording	last  message  UIDs  seen  per
	    host.

       ~/.fetchmail.pid
	    lock file to help prevent concurrent runs (non-root mode).

       ~/.netrc
	    your FTP run control file, which (if present) will be searched for
	    passwords as a last resort before prompting for one interactively.

       /var/run/fetchmail.pid
	    lock file to help prevent concurrent runs (root mode,  Linux  sys‐
	    tems).

       /etc/fetchmail.pid
	    lock  file	to  help  prevent  concurrent runs (root mode, systems
	    without /var/run).

ENVIRONMENT
       FETCHMAILUSER: If the FETCHMAILUSER variable is set, it is used as  the
       name  of	 the  calling  user  (default local name) for purposes such as
       mailing error notifications.  Otherwise, if either the LOGNAME or  USER
       variable	 is correctly set (e.g. the corresponding UID matches the ses‐
       sion user ID) then that name is used as the default local name.	Other‐
       wise getpwuid(3) must be able to retrieve a password entry for the ses‐
       sion ID (this elaborate logic is designed to handle the case of	multi‐
       ple names per userid gracefully).

       FETCHMAILHOME:  If  the	environment variable FETCHMAILHOME is set to a
       valid and existing directory  name,  fetchmail  will  read  $FETCHMAIL‐
       HOME/fetchmailrc	 (the  dot  is	missing	 in  this  case),  $FETCHMAIL‐
       HOME/.fetchids and $FETCHMAILHOME/.fetchmail.pid rather than  from  the
       user's home directory.  The .netrc file is always looked for in the the
       invoking user's home directory regardless of FETCHMAILHOME's setting.

       HOME_ETC:  If  the  HOME_ETC  variable  is  set,	 fetchmail  will  read
       $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.

       If HOME_ETC and FETCHMAILHOME are both set, HOME_ETC will be ignored.

       SOCKS_CONF:  (only  if  SOCKS  support is compiled in) this variable is
       used by the socks library to  find  out	which  configuration  file  it
       should read. Set this to /dev/null to bypass the SOCKS proxy.

SIGNALS
       If  a fetchmail daemon is running as root, SIGUSR1 wakes it up from its
       sleep phase and forces a poll of all non-skipped servers. For  compati‐
       bility  reasons, SIGHUP can also be used in 6.3.X but may not be avail‐
       able in future fetchmail versions.

       If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
       it  (this  is  so SIGHUP due to logout can retain the default action of
       killing it).

       Running fetchmail in foreground while a background fetchmail is running
       will do whichever of these is appropriate to wake it up.

BUGS AND KNOWN PROBLEMS
       Please  check  the NEWS file that shipped with fetchmail for more known
       bugs than those listed here.

       Fetchmail cannot handle user names that	contain	 blanks	 after	a  "@"
       character, for instance "demonstr@ti on". These are rather uncommon and
       only hurt when using UID-based --keep setups, so the 6.3.X versions  of
       fetchmail won't be fixed.

       The  assumptions	 that the DNS and in particular the checkalias options
       make are not often sustainable. For instance, it	 has  become  uncommon
       for  an	MX server to be a POP3 or IMAP server at the same time. There‐
       fore the MX lookups may go away in a future release.

       The mda and plugin options interact badly.  In order to	collect	 error
       status from the MDA, fetchmail has to change its normal signal handling
       so that dead plugin processes don't get reaped until  the  end  of  the
       poll  cycle.   This  can	 cause resource starvation if too many zombies
       accumulate.  So either don't deliver to a MDA  using  plugins  or  risk
       being overrun by an army of undead.

       The  --interface	 option does not support IPv6 and it is doubtful if it
       ever will, since there is no  portable  way  to	query  interface  IPv6
       addresses.

       The  RFC822  address  parser  used  in  multidrop  mode	chokes on some
       @-addresses that are technically legal but bizarre.   Strange  uses  of
       quoting and embedded comments are likely to confuse it.

       In  a  message  with  multiple envelope headers, only the last one pro‐
       cessed will be visible to fetchmail.

       Use of some of these protocols requires that  the  program  send	 unen‐
       crypted	passwords  over the TCP/IP connection to the mailserver.  This
       creates a risk that name/password pairs might be snaffled with a packet
       sniffer	or  more  sophisticated	 monitoring software.  Under Linux and
       FreeBSD, the --interface option can be  used  to	 restrict  polling  to
       availability  of	 a  specific interface device with a specific local or
       remote IP address, but snooping is still possible if  (a)  either  host
       has a network device that can be opened in promiscuous mode, or (b) the
       intervening network link can be tapped.	We recommend the use of ssh(1)
       tunnelling  to  not  only  shroud your passwords but encrypt the entire
       conversation.

       Use of the %F or %T escapes in an mda  option  could  open  a  security
       hole, because they pass text manipulable by an attacker to a shell com‐
       mand.  Potential shell characters are replaced by '_' before execution.
       The hole is further reduced by the fact that fetchmail temporarily dis‐
       cards any suid privileges it may have while running the MDA.  For maxi‐
       mum  safety, however, don't use an mda command containing %F or %T when
       fetchmail is run from the root account itself.

       Fetchmail's method of sending bounces due to  errors  or	 spam-blocking
       and  spam  bounces  requires that port 25 of localhost be available for
       sending mail via SMTP.

       If you modify a ~/.fetchmailrc while a background instance  is  running
       and  break  the	syntax,	 the  background  instance  will die silently.
       Unfortunately, it can't die noisily because we don't yet	 know  whether
       syslog should be enabled.  On some systems, fetchmail dies quietly even
       if there is no syntax error; this seems to have something  to  do  with
       buggy terminal ioctl code in the kernel.

       The  -f	-  option (reading a configuration from stdin) is incompatible
       with the plugin option.

       The 'principal' option only handles Kerberos IV, not V.

       Interactively entered passwords are truncated after 63  characters.  If
       you  really  need to use a longer password, you will have to use a con‐
       figuration file.

       A backslash as the last character  of  a	 configuration	file  will  be
       flagged as a syntax error rather than ignored.

       The  BSMTP error handling is virtually nonexistent and may leave broken
       messages behind.

       Send comments, bug reports, gripes, and the like to the fetchmail-devel
       list  <fetchmail-devel@lists.berlios.de>.   An HTML FAQ is available at
       the fetchmail home page; surf to http://fetchmail.berlios.de/ or	 do  a
       WWW search for pages with 'fetchmail' in their titles.

AUTHOR
       Fetchmail  is currently maintained by Matthias Andree and Rob Funk with
       major assistance from Sunil Shetye (for code) and  Rob  MacGregor  (for
       the mailing lists).

       Most  of the code is from Eric S. Raymond <esr@snark.thyrsus.com>.  Too
       many other people to name here have contributed code and patches.

       This program is descended from and replaces popclient, by  Carl	Harris
       <ceharris@mal.com>; the internals have become quite different, but some
       of its interface design is directly traceable to	 that  ancestral  pro‐
       gram.

       This  manual  page  has	been  improved by R. Hannes Beinert and Héctor
       García.

SEE ALSO
       mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)

       The fetchmail home page: <http://fetchmail.berlios.de/>

       The maildrop home page: <http://www.courier-mta.org/maildrop/>

APPLICABLE STANDARDS
       Note that this list is just a collection of references and not a state‐
       ment  as	 to  the actual protocol conformance or requirements in fetch‐
       mail.

       SMTP/ESMTP:
	    RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC	1870,  RFC  1983,  RFC
	    1985, RFC 2554.

       mail:
	    RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.

       POP2:
	    RFC 937

       POP3:
	    RFC	 1081,	RFC  1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC
	    1957, RFC 2195, RFC 2449.

       APOP:
	    RFC 1939.

       RPOP:
	    RFC 1081, RFC 1225.

       IMAP2/IMAP2BIS:
	    RFC 1176, RFC 1732.

       IMAP4/IMAP4rev1:
	    RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061,  RFC  2195,  RFC
	    2177, RFC 2683.

       ETRN:
	    RFC 1985.

       ODMR/ATRN:
	    RFC 2645.

       OTP: RFC 1938.

       LMTP:
	    RFC 2033.

       GSSAPI:
	    RFC 1508.

       TLS: RFC 2595.

fetchmail			fetchmail 6.3.8			  fetchmail(1)
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