Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!decwrl!labrea!csli!gandalf
From: gandalf@csli.STANFORD.EDU (Juergen Wagner)
Newsgroups: comp.mail.sendmail
Subject: Re: Isn't rule 0 the final path?
Message-ID: <7441@csli.STANFORD.EDU>
Date: 6 Feb 89 06:02:24 GMT
References: <1459@vicom.COM>
Reply-To: gandalf@csli.stanford.edu (Juergen Wagner)
Organization: Center for the Study of Language and Information, Stanford U.
Lines: 21

The process of finding a mailer/host/mailbox is not just captured by rulesets
3 and 0. The function parseaddr which
	"Parses an address and breaks it up into three parts: a
	 net to transmit the message on, the host to transmit it
	 to, and a user on that host."
does the following:

o  parse the address into tokens;
o  rewrite it by ruleset #3 (canonicalization);
o  rewrite it by ruleset #0 (giving $# mailer $@ host $: mailbox);
o  call buildaddr to build an address from the resulting specification.

Now, buildaddr checks the mailer and the host, and then calls ruleset #2 to
do recipient rewriting, calls the mailer-specific recipient rewriting ruleset,
and calls ruleset #4 to clean up everything (externalize).

To summarize, there is more to it than just #3 and #0.

-- 
Juergen Wagner		   			gandalf@csli.stanford.edu
						 wagner@arisia.xerox.com