Chapter 12. Maintain Aliases

Aliasing is the process of replacing one recipient address with one or more different recipient addresses. The replacement address can be that of a single user, a list of recipients, a program, a file, or any mixture of these. In this chapter we cover the aliases(5) file, one of the three methods of aliasing available with the sendmail program. We will cover the other two forms, :include: (for including separate files from within the aliases file) and ~/.forward (the user's personal :include: file), in the next chapter.

Aliasing can be used to handle several complex delivery problems:

• Delivering mail to a single user under a variety of usernames

• Distributing a mail message to many users by specifying only a single recipient name

• Appending mail to files for archival and other purposes

• Filtering mail through programs and shell scripts

All the information that is needed to perform these tasks is contained in the aliases(5) file (which is often also stored in database format to expedite the lookup process).