The Mail Manager

Managing masquerading

The ``Mail Comes From'' entry configures masquerading for sendmail. Masquerading allows you to specify the mail address format for all users, resulting in a mail message that appears to come from a host name of your choosing. This feature is often used to hide the current host name behind the domain name. For example, suppose that you have some users sending mail from a machine with the fully qualified host name mailsrvr1.devt.footle.com, and other users sending mail from machine mailsrvr2.mktg.footle.com, but you would really prefer all outgoing messages to appear as being sent from a single source. You could change the ``Mail Comes From'' value to footle.com for both machines so that all messages would have a sender address that appears in the format user@footle.com and it appears that mail comes from footle.com.

The ``Mail Comes From'' name may be selected from the list of choices presented, or a different name may be typed into the text field. The sendmail.cf file in UnixWare^® has a specially defined macro to implement masquerading, named ``M''. The Mail Manager changes the value of the macro accordingly. Then the M macro is used in the address-rewriting rulesets that are defined for delivery agents.

To change the ``Mail Comes From'' entry and display the results:

Highlight the ``Mail Comes From'' entry on the main screen.
Click on Modify.
A screen pops up with a list of suggestions to allow you to select the machine name or domain.
Select the machine name on domain you require in the ``Mail Comes From'' field.
Click on OK to confirm your selection and return to the main screen.

NOTE: By default, sendmail masquerading is bypassed for user root. Therefore, mail from root always appears with a sender address that has the fully qualified domain name. The default can only be changed by hand-editing the E class macro in /etc/sendmail.cf. Look fo the following line in etc/sendmail.cf:

   CEroot

Every user listed after the ``CE'' will bypass masquerading. To allow masquerading for root, change the line to the following:

CE

To add additional users whom you wish to bypass masquerading, add them to the CE line. For example, if you wish to add user george to this list, modify the CE line as follows:

   CEroot george