sendmail, 4th Edition

$x

The full name of the sender All versions

The $x macro holds the full name of the sender. When sendmail processes a mail message for delivery, it rewrites the sender’s address using the canonify rule set 3 and the parse rule set 0 so that it can determine whether the sender is local. If the sender is local, the parse rule set 0 provides the sender’s login name with the $: operator. Then, if the delivery agent’s F=w flag (F=w on page 781) is set,^[327] the login name is looked up using the method defined by the MailboxDatabase option (MailboxDatabase on page 1042).^[328] If the login name is known, the sender’s full name is returned. If necessary, that full name is then processed, throwing away phone numbers and the like and converting the & character. The result, usually fairly close to the sender’s actual full name, is the value assigned to the $x macro.

Under certain circumstances, sendmail places a different value in $x:

• When sendmail first starts to run, it sets the full name to be the value of the NAME environment variable, and places that value into $x.

• The -F command-line switch (-F on page 240) can overwrite the value in the $x macro.

• If the operating mode is -q (Periodically with -q on page 427) or -bd (-bd on page 234), the value in $x is reset to NULL.

• In processing the headers of a message, if sendmail finds a Full-Name: header (Full-Name: on page 1158), it assigns the text of that header to the $x macro.

• In sending a failed mail message, the login name of the sender is taken ...