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Posting-Version: version B 2.10 5/3/83; site cbosgd.UUCP
Path: utzoo!linus!philabs!cmcl2!floyd!harpo!eagle!mhuxl!cbosgd!mark
From: mark@cbosgd.UUCP (Mark Horton)
Newsgroups: net.mail
Subject: Re: Loop detection...
Message-ID: <758@cbosgd.UUCP>
Date: Fri, 23-Dec-83 00:16:41 EST
Article-I.D.: cbosgd.758
Posted: Fri Dec 23 00:16:41 1983
Date-Received: Sat, 24-Dec-83 10:38:38 EST
References: <4666@decwrl.UUCP>, <396@sun.uucp>
Organization: AT&T Bell Laboratories, Columbus
Lines: 9

On the other hand, if you store a recent history on your machine
(like the mechanism netnews uses), you can store the pair
	(Message-ID, Destination)
locally, and if it repeats, you know you have a loop.  This assumes
that (a) the message has a Message-ID (it isn't required by RFC822,
although some programs, like sendmail, add one if the message doesn't
already have one) and that somebody hasn't written an idiot reply
command that duplicates the Message-ID (amazingly enough, this isn't
forbidden by 822).