Since the early days of networked computing email has been used for group comunications which takes advantage of the ability to address an email message to multiple receipients. SDF hosts several email lists or mlists which are managed via Majordomo, an mlist manager. Unlike more modern mlist managers which generally have a web interface, Majordomo interaction is via short commands sent via email to majordomo@sdf.org (the domain may be left off when logged into SDF shell session). These commands and more are documented in the majordomo(8) manpage (type man majordomo to view within your SDF shell session). A condensed help offering is also available via the 'help' commands sent directly to Majordomo.

Although there are several commands listed in the Majordomo documentation users only needs to know a few of them. For simplicity the examples below make use of the native BSD mail(1) email client used within an SDF shell session:

# get a list of SDF hosted email lists:
$ echo 'list' > mail -s 'SDF mlists' majordomo@sdf.org
 
# subcribe to a list:
$ echo 'subscribe XYZ' > mail -s 'Subscribe to XYZ' majordomo@sdf.org

# unsubscribe to a list:
$ echo 'unsubscribe XYZ' > mail -s 'Unsubscribe to XYZ' majordomo@sdf.org

If you wish to subscribe using an email address other than the one associated with your SDF account simply append it to the end of the command line:

# subscribing to list XYZ using some other email address:
$ echo 'subscribe XYZ me2@frog.bog' > mail -s 'Subscribe to XYZ' majordomo@sdf.org''

For security mlist subscription requests generally require a one-time authorization be sent back to majordomo@sdf.org, similar to when setting up an online account on the Internet.

• majordomo v1 FAQ (mostly of interest to admins): http://manual.sdf.org/majordomo/FAQ
• majordomo wikipedia page: https://en.wikipedia.org/wiki/Majordomo_(software)
• archive of GreatCircle.com/majordomo: https://web.archive.org/web/20120102123822/http://www.greatcircle.com/majordomo/

• Managing Mailing Lists: Majordomo, LISTSERV, Listproc, and SmartList by Alan Schwartz
• Managing Internet Information Services by Cricket Liu & associates