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From: MRC%PANDA@SUMEX-AIM.STANFORD.EDU.UUCP
Newsgroups: mod.protocols.tcp-ip
Subject: Re: When to acknowledge SMTP messages
Message-ID: <12282235123.9.MRC@PANDA>
Date: Thu, 26-Feb-87 19:12:35 EST
Article-I.D.: PANDA.12282235123.9.MRC
Posted: Thu Feb 26 19:12:35 1987
Date-Received: Sat, 28-Feb-87 06:27:04 EST
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Kevin Crowston -

     Your relay should queue the message on its local disk and acknowledge
it once it is safely written.  That protects against the system crash
problem.  If the message cannot be accepted by the other end, then the
message should be returned to the sender via the return-path address.

     An SMTP server should NEVER block a client waiting for delivery.
It is STUPID and WRONG-HEADED to keep an SMTP connection open for ANY
period of time longer than is necessary to get the bits across and
acknowledged.

     The world isn't necessarily the Internet with no charges per packet
or time charges for a virtual circuit.  When time charges are a reality,
mail servers that block clients COST REAL MONEY.

     Sorry for flaming, but this really is an important concept.

-- Mark --
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