Path: utzoo!attcan!uunet!aplcen!samsung!zaphod.mps.ohio-state.edu!mips!decwrl!ucbvax!w107zrz.zrz.tu-berlin.de!elsn4000
From: elsn4000@w107zrz.zrz.tu-berlin.de (Frank Elsner)
Newsgroups: comp.protocols.tcp-ip
Subject: sendmail.cf
Message-ID: <9008281226.AA28367@w107zrz.zrz.tu-berlin.de>
Date: 28 Aug 90 12:26:42 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 23

I've a few questions about ruleset 0 in sendmail.cf

The following is defined in sendmail.cf:

# Supersmart relay.  Used when all other attempts to deliver fail
DSmailgzrz.tu-berlin.de
# UUCP relay host
DRmailgzrz.tu-berlin.de

The following rule from ruleset 0 works correct:
R$*<@$*.UUCP>$*		$#tcp$@$[$R$]$:$1<@$2.UUCP>	uucp mail

but the following rule also works correct:
R$*<@$*.UUCP>		$#tcp$@$S$:$1@$2.UUCP		user@host.UUCP

The question for me is "Why do both rules work correctly ?"
What is the meaning of the "[" and "]" on the RHS ?
Why are sometimes "<" and ">"  on the RHS and sometimes not ?

Thanks for enlightning a sendmail beginner.
Frank Elsner
Postmaster at  Central Computing Center
               Technical University Berlin (West, until Oct 3)