From: Robert_Ullmann/CAM/
Date: Sun Aug 03 1997 - 22:55:39 EDT

Standard is :looks like an error message:?

US MIL-STD-1781 (aka RFC 821, "SMTP", with has no standards status at all,
there being no standards body recognizing it with anything even vaguely
resembling legal status) specifies that errors must be sent *only* to the
SMTP return-path (the MAIL From: address in the protocol) and that when
errors are sent, the return path is be <> (i.e. null).

This works *every*single*time*, but is much ignored by people who prefer
neat-but-seriously-broken hacks over real engineering.

Mail list expanders must therefore not modify the return path if they want
to prevent loops.

Don't believe me: go read it. (Not the RFC! THE MIL STD, the real
[expletive deleted] standard).

Robert ("Markus G. Kuhn") on 08/03/97 01:19:32 PM

Please respond to

To: Multiple Recipients of <>
cc: (bcc: Robert Ullmann/CAM/Lotus)

"Richard Tuttle" wrote on 1997-08-03 23:51 UTC:
> Why am I getting this ALL THE TIME?
What happens is that there is a configuration error on the
site, which returns an error message because a message
was not delivered. Unfortunately, the error message is sent to
the Reply-To: address, i.e. the entire Unicode mailing list. Unfortunately,
this causes again the error message to be sent back to, which
triggers another error message. It seems that the fundamental law of
networking that says "NEVER reply with an error message on anything that
looks like an error message" has been violated here by this strange site. This subscriber should be removed from the Unicode
mailing list until they install less dangerous e-mail software. In the
meantime, use a mailing filter like procmail to discard those messages

Markus G. Kuhn, Computer Science grad student, Purdue
University, Indiana, USA -- email:

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