About mail and news
The broad use of Linux for mail and news servers has led to the development of improved tools over time. When the LPI certification exams were developed, the most popular tools were Sendmail for mail transport, Procmail for local mail handling, Majordomo for mailing lists, and innd (InterNetNews daemon) for NNTP. The last of these is still probably the default choice for news; however, despite its technical strengths, the NNTP protocol has been somewhat eclipsed by e-mail mailing lists and Web-based discussion forums.
Of the other tools, Sendmail and Procmail are still widely used, although not as ubiquitously as they once were. The most popular upgrade or replacement for Sendmail is postfix, which contains facilities for backwards compatibility with Sendmail. The local mail handling field is well populated with choices, but Procmail is still popular. On the other hand, Majordomo is a slight anachronism nowadays. Just as Majordomo largely replaced the earlier listserv software, mailman has more recently eclipsed Majordomo. However, to match the current LPI topic areas, this tutorial discusses Majordomo.
As with most Linux tools, it is always useful to examine the man pages for any utilities discussed. Versions and switches might change between utility or kernel version or with different Linux distributions. For more in-depth information, the Linux Documentation Project has a variety of useful documents, especially its HOWTOs. See the Resources section for a link. A variety of books on Linux networking have been published; I have found O'Reilly's TCP/IP Network Administration, by Craig Hunt, to be quite helpful (find whatever edition is most current when you read this; see Resources for a link).