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From: smb@ulysses.UUCP (Steven Bellovin)
Newsgroups: net.mail.headers
Subject: Re:  What are SMTP commands "EXPN" and "VRFY" good for?
Message-ID: <8409160205.AA15551@kalypso.UUCP>
Date: Sat, 15-Sep-84 22:05:49 EDT
Article-I.D.: hou3c.832
Posted: Sat Sep 15 22:05:49 1984
Date-Received: Thu, 4-Oct-84 02:45:23 EDT
Sender: ka@hou3c.UUCP (Kenneth Almquist)
Lines: 16
To: header-people@mit-mc.ARPA, wales@ucla-locus.ARPA

Except for the problem of failed mail in a list expansion -- on which
matter I agree with Rich Wales -- EXPN struck me as a good idea for
handling mail to multiple lists, or to a person and a list.  As is,
Rich is going to receive two copies of this letter -- one direct, and
one via the list expansion.  A sufficiently smart mailer could use
EXPN to discover that Rich is on the list, and not send him a separate
copy.  (We'll ignore the fact that this particular note is going via
uucp to an SMTP host; it wouldn't really change anything if it weren't.)


	--Steve Bellovin
	AT&T Bell Laboratories

	ulysses!smb@berkeley.arpa
	smb.ulysses.btl@csnet-relay	(should work, but probably doesn't)
	smb.research.btl@csnet-relay	(works more often)