sendmail, 4th Edition

$U

The UUCP name to override $k mc configuration

When configuring with the mc configuration technique, you can include support for UUCP by using the MAILER(uucp) command (MAILER( ) m4 macro on page 590) in your mc file. With that support, you can override the use of $k ($k on page 831) with a hostname of your choosing when prefixing a string of hosts with the local hostname:

here!lady!sonya!user
↑
insert local hostname here

If $U has a value, its value will be inserted. If it lacks a value, $k will be inserted.

$U can be useful when several hosts provide UUCP services. It can be defined in your DOMAIN( ) file (DOMAIN( ) m4 macro on page 591) as a single name so that all outgoing UUCP mail will appear as though it is from a common host.