The mail transport method to use. The three acceptable options are
.B smtp
(which is the default),
-.BR sendmail ,
+.BR sendmail/smtp ,
and
-.BR pipe .
+.BR sendmail/pipe .
.PP
If you use
.BR smtp ,
entry.
.PP
If you use
-.BR sendmail ,
+.BR sendmail/smtp ,
then
.B post
will send messages by forking a
.BR sendmail .
It will still speak SMTP with this local copy of
.BR sendmail .
+For backward compatibility,
+.B sendmail/smtp
+can be abbreviated to
+.BR sendmail .
.PP
The third alternative,
-.BR pipe ,
+.BR sendmail/pipe ,
also forks a local copy of
.B sendmail
but feeds the message directly to it, using