sendmail, 4th Edition

-p

Set protocol and host V8.10 and later

The $r sendmail macro ($r on page 842) holds as its value the protocol that is used in receiving a mail message (usually SMTP or UUCP). The $s sendmail macro ($s on page 844) holds as its value the name of the sending host. Some programs, such as UUCP, need to be able to set the values of these macros from the command line. The old way to set them looked like this:

-oMrUUCP -oMslady

Here, the M option sets $r to be UUCP and $s to be lady.

Under V8 sendmail, the setting of $r and $s has been simplified. A command-line single switch, -p, can be used to set them both:

-prval:sval

Here, the rval is the value assigned to $r, and the sval is the value assigned to $s. The two are separated by a colon. If the sval is omitted, the colon should also be omitted.