sendmail, 4th Edition

The aliases(5) File’s Location

The location of aliases(5) is specified with the ServiceSwitchFile option (ServiceSwitchFile on page 1088) and the AliasFile option (AliasFile on page 970) in the configuration file. Be aware that because these two options interact, it might not suffice to simply declare one or the other. Also be aware that some systems (such as Solaris) supply service-switch files that will override the ServiceSwitchFile option’s setting.

Note that the service-switch file merely specifies the order in which various methods should be used to look up aliases, not the specific files. If it lists files as a method:

aliases    files

all the files declared with the AliasFile option will be looked up in the order in which they were declared:

• If the AliasFile option specifies a file and if a service-switch file omits the files specification, the AliasFile option is ignored.

• If the AliasFile option specifies a file and if a service-switch file omits the aliases line, the AliasFile option is used.

• If the AliasFile option specifies a file and if there is no service-switch file, the AliasFile option file is used, except on systems that implement their own service-switch files.

• If the AliasFile option is omitted and if there is no service-switch file or if there is a service-switch file but it omits an aliases line, sendmail silently presumes that it should not do aliasing.

Note that service-switch files and the AliasFile option can list other techniques for obtaining aliases in addition ...