On Mon, 27 Mar 2000 17:12:39 -0400, Bruce Dienes <[log in to unmask]> wrote:

>I'm assuming that the "relay" error occurs because mail from a LISTSERV list uses the list address as the To: line, meaning that the server will see that the message is neither from nor addressed to any address in its domain, and so assumes it is a relay.

Not so, unless it a badly misconfigured mail server (which is certainly
possible!)  All SMTP email travels in an 'envelope'.  The envelope includes a
'return-path' address (for the the reporting if any delivery errors, just like
snail mail) and a 'forward-path' addres for the recipient(s).  Unlike snail mail
it is technically possible to have multiple recipients (in the same domain) in
one 'envelope'.  e.g.

MAIL FROM:<[log in to unmask]>
RCPT TO:<[log in to unmask]>
RCPT TO:<[log in to unmask]>
RCPT TO:<[log in to unmask]>

In this case only one copy of the message is delivered to aol.com and aol makes
the necessary 'copies' for each individual mailbox.  SMTP Protocol (defined in
RFC821) requires the final receiving SMTP server to 'open' the 'envelope' and
discard it, (preserving only the SMTP Return-Path: header line for the purpose
of error reporting).  This is called BSMTP and is actually how LISTSERV delivers
mail without using CC: or BCC: methods and seemingly without using the
recipient's own email address.

The headers of the actual message will say
To: [log in to unmask]
From: [log in to unmask]
Date: ...
Subject: ...

but these headers are part of the message body as specified by RFC822 and are
NOT used for the actual SMTP mail delivery at all so it doesn't matter what they
say (at least as far as SMTP is concerned.  The may still be important to you.)