ietf-smtp
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Re: Keep Alive Response Codes

2005-09-15 05:57:12

On Thu, 15 Sep 2005, Frank Ellermann wrote:

So if we would find that 1xx doesn't work at all in 2821,
- maybe it's just a historic error in (2)821 (?) - then we
could still note this idea for a future 2476ter.

I'm somewhat baffled by this discussion about trying to add client
keepalives to SMTP, especially the evil non-standard hacks that people
are suggesting. What is not clear about the following text?

            1yz   Positive Preliminary reply

               The command has been accepted, but the requested action
               is being held in abeyance, pending confirmation of the
               information in this reply.  The sender-SMTP should send
               another command specifying whether to continue or abort
               the action.

                  [Note: SMTP does not have any commands that allow this
                  type of reply, and so does not have the continue or
                  abort commands.]

Note also that there is no way you can tell which line of the reply a
client will examine to extract the reply code. If the server's reply is
inconsistent the client may consider the server to be insane, or may get
its reply pipeline out of step, or it may simply misunderstand.

If you want to add keepalives, write an ESMTP service extension.

Tony.
-- 
f.a.n.finch  <dot(_at_)dotat(_dot_)at>  http://dotat.at/
BISCAY: WEST 5 OR 6 BECOMING VARIABLE 3 OR 4. SHOWERS AT FIRST. MODERATE OR
GOOD.