Path: utzoo!utgpu!watserv1!watmath!att!att!emory!swrinde!zaphod.mps.ohio-state.edu!usc!apple!agate!shelby!morrow.stanford.edu!ack.Stanford.EDU!pst
From: pst@ack.Stanford.EDU (Paul Traina)
Newsgroups: comp.mail.sendmail
Subject: Re: Sendmail 5.64 (Berkeley) coughs up an error on local SMTP
Keywords: help!
Message-ID: <pst.656708546@ack.Stanford.EDU>
Date: 23 Oct 90 19:02:26 GMT
References: <6828@uwm.edu> <3976@awdprime.UUCP>
Sender: news@morrow.stanford.edu (UNIX News Service)
Organization: Data Center, Stanford University, California, USA
Lines: 14

There are two cases involved here...

(a) sendmail should NEVER EVER EVER talk to itself.  There is no reason
    for it to do so.  Anything that can be done by sending the message
    back to itself should be done in the .cf file.  Otherwise you run
    the risk of nasty infinite loops.

(b) some programs (like mh with sendmail/smtp) could possibly connect
    to the local host, send down a "valid" hostname in the HELO greeting,
    and get trapped.  The simple solution is to not issue a HELO,  but
    that my break the smtp RFC.  The other idea would be to issue HELO
    localhost, but some wise-ass :-) (you know who you are)  may have
    sendmail bitch about people sending down HELO messages with bogus
    sites in them.