🚀 go-pugleaf

In article <DOUG.89Feb3140955@csd4.milw.wisc.edu> doug@csd4.milw.wisc.edu (Doug Tiarks) writes:
> From what I've seen so far it appears that sendmail takes the resulting
> address from ruleset 0 (mailer, host, address triple) and passes it on to
> rulesets 2 -> mailer specific -> 4 before using it in the address for the
> mailer. This is certainly not what the Sendmail Installation Guide would
> have one believe. 
>
> For the case of the IPC mailer the ruleset path  would look like:
>
> from   -> 3  -> 0 -> address from  -> 2 -> mailer -> 4  -> SMTP RCPT TO:
> address	       mailer, host,	     specific	     command
> 		       address triple

You are right about the S4; not sure about the S2.  From src/Version.c:

< D 5.26	85/09/25 11:02:19	eric	448	447	00000/00000/00015
< DO use Ruleset 4 when defining $f -- it's very necessary (fix for <>
< will have to be done in configuration); pretty up mailq -v slightly

< D 5.23	85/09/23 21:19:05	eric	445	444	00000/00000/00015
< deliver directly in SMTP if VERB command has been issued; don't
< externalize name using ruleset 4 when defining $f macro: this turns "<>"
< into "", which confuses local mail

So, from versions 5.23 -> 5.26 is was true that the final address does not
go through S4.  Now, however, it does.  Note that S4 is only used for the
$: portion of the triple.
-- 
Mark Sirota - University of Rochester, Rochester, NY
 Internet: msir@cc.rochester.edu
 Bitnet:   msir_ss@uordbv.bitnet
 UUCP:     ...!rochester!ur-cc!msir

The pre-defined role of rulesets is as follows:

0       determine mailer for delivery. returns: <mailer,host,mailbox>
1       sender rewriting
2       recipient rewriting
3       canonicalization
4       externalization

with IDA, one has separate envelope/header rewriting, i.e.

5       sender rewriting (headers, #1 is for envelope in such systems)
6       recipient rewriting (headers, #2 is for envelopes).

Now, what happens when you ask sendmail to deliver a mesage is roughly the
following:

recipient -> canonicalize -> find_mailer -> $# mailer $@ host $: mailbox
	 	#3		 #0
		|
		+--> #2 (or #6) -> recipient'

The mailbox is transformed as

mailbox -> recipient rw. -> mailer-specific -> externalize -> mailbox'
	     #2		    rewriting rule       #4

Mail is then delivered to |mailbox'| on |host|, using |mailer| (and also
its interpretation of |host| and |mailbox|). The To: header field will
contain |recipient'|.

Similar transformations are done with the sender field but there is no call
to ruleset #0:

sender -> canon. -> sender rw. -> mailer-specific -> externalize -> sender'
	    |			  rewriting rule
	    |
	    +--> sender rw. (#1 or #5) -> sender"

Now, what you will see is:

Message Header - 	From: sender"
			To: recipient'

Message Envelope -	RCPT To: mailbox'
			MAIL From: sender'
	while talking SMTP to "host".

Of course, with other mailers, the dialogue looks a little different, but
basically the envelope/header structure remains the same.

[I hope I've got all these arrows right.]

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