sendmail, 4th Edition

EXPOSED_USER mc Macro

An internal sendmail class is used by the V8 configuration file to hold a list of usernames that should never be masqueraded (even if masquerading is enabled with the MASQUERADE_AS mc macro). Prior to V8.10 sendmail, the user root was always in that class. With V8.10 and later, that class is now always empty unless you add usernames into it.

You can add users individually with the EXPOSED_USER mc macro like this:

EXPOSED_USER(`user')

Here, user is either one user or a list of users separated by spaces.

EXPOSED_USER_FILE mc macro

The EXPOSED_USER_FILE macro, like the EXPOSED_USER macro, allows you to list names that should never be masqueraded (even if masquerading is enabled with the MASQUERADE_AS mc macro). It lists usernames in an external file, one name per line, and is declared like this:

EXPOSED_USER_FILE(`/etc/mail/exposedusers')

This declaration causes a list of users to be read from the file /etc/mail/exposedusers. Because EXPOSED_USER_FILE is implemented with an F configuration command (The F Class Command on page 857), you can add whatever F command arguments you desire. For example:

EXPOSED_USER_FILE(`-o /etc/mail/exposedusers')

Here the -o switch makes the presence of the /etc/mail/exposedusers file optional.

If you are currently reading exposed users from a file declared with the F configuration command, you are encouraged to convert to this new macro. Use of it will insulate you from change in the future if a different class name is ever used.