sendmail, 4th Edition

Specialty Programs for Use with ~/.forward

Rather than expecting users to write home-grown programs for use in ~/.forward files, offer them any or all of the publicly available alternatives. The most common are listed in the following sections.

The procmail program

The procmail(1) program, originally written by Stephen R. van den Berg and currently maintained by Philip Guenther, is purported to be the most reliable of the delivery programs. It can sort incoming mail into separate folders and files, run programs, preprocess mail (filtering out unwanted mail), and selectively forward mail elsewhere. It can function as a substitute for the local delivery agent or handle mail delivery for the individual user. The procmail program (as recommended in its manual) is typically used in the ~/.forward file like this:

"|exec /usr/local/bin/procmail #user"

Note that procmail does not accept a username as a command-line argument. Because of this, a dummy shell comment is needed for pre-V8 versions of sendmail to make the address unique. The procmail program is available from the site http://www.procmail.org/.

The slocal program

The slocal program, distributed with the mh distribution, is useful for sorting incoming mail into separate files and folders. It can be used with both Unix-style mail files and mh-style mail directory folders. The slocal program (as recommended in its manual) is typically used in the ~/.forward file like this:

"| /usr/local/lib/mh/slocal -user user"

The disposition of mail is ...