Mail to Files and Programs

Files and programs are legitimate message recipients. Files provide archival storage of messages, useful for project administration and history. Programs are useful as recipients in a variety of situations, for example, to use mailsort to sort mail or to have the vacation program respond with an informational message when users are away.

Any name passing through the initial parsing algorithm as a local name is scanned for two special cases:

• If the prefix is a vertical bar (|), the rest of the name is processed as a shell command.

• If the user name begins with a slash (/), the name is used as a file name instead of a login name.