DMAIL(LOCAL)DMAIL(LOCAL)NAMEdmail - procmail Mail Delivery Module
SYNOPSISdmail [-D] [-f from_name] [user][+folder]
DESCRIPTIONdmail delivers mail to a user's INBOX or a designated
folder. dmail may be configured as a drop-in replacement
for binmail(1), mail.local(1) for use with a mail delivery
filter such as procmail(1).
Because of security considerations (see below) dmail is
not intended to be used for direct delivery by the mailer
daemon; tmail(1) is the preferred tool for this purpose.
If dmail is used for mailer daemon delivery, the mailer
daemon must invoke dmail with the dmail process' user id
set to the recipient's user id.
When dmail exits, it returns exit status values to enable
procmail(1) to determine whether a message was delivered
successfully or had a temporary (requeue for later
delivery) or permanent (return to sender) failure.
If the user name is present, it must be the same as the
logged-in user name.
If the +folder extension is included in the user argument
(or appears by itself if there is no user argument), dmail
will attempt to deliver to the designated folder. If the
folder does not exist or the extension is not included,
the message is delivered to the user's INBOX. If delivery
is to INBOX and no INBOX currently exists, dmail will
create a new INBOX, using the -I flag if specified. dmail
recognizes the format of an existing INBOX or folder, and
appends the new message in that format.
The -D flag specifies debugging; this enables additional
message telemetry.
The -f or -r flag is used to specify a Return-Path. The
header
Return-Path: <from_name>
is prepended to the message before delivery.
RESTRICTIONS
Absolute pathnames and ~user specifications are not
permitted in +folder extensions.
SECURITY CONSIDERATIONS
Unlike tmail you can use dmail to deliver to IMAP4
namespace names via +folder extensions. This means that
it is possible to deliver to mh(1) format mailboxes.
However, this can also include such namespaces as #shared,
#public, and #ftp. In most cases, it is undesirable to
allow anybody sending mail to the user to deliver to these
namespaces. Consequently, there needs to be a rule in
place in the configuration of either sendmail(8) or
procmail(1) to prevent such abuse.
AUTHOR
Mark Crispin, MRC@CAC.Washington.EDU
SEE ALSObinmail(1)procmail(1)
Version 4.1 DMAIL(LOCAL)
