Chapter 10. sendmail

Users have a love-hate relationship with email: they love to use it, and hate when it doesn’t work. It’s the system administrator’s job to make sure it does work. That is the job we tackle in this chapter.

sendmail is not the only mail transport program; smail and qmail are also popular, but plain sendmail is the most widely used mail transport program. This entire chapter is devoted to sendmail, and an entire book can easily be devoted to the subject.^[109] In part, this is because of email’s importance, but it is also because sendmail has a complex configuration.

^[109] See sendmail by Costales and Allman (O’Reilly & Associates) and Linux Sendmail Administration by Craig Hunt (Sybex) for book-length treatments of sendmail.