ietf-smtp
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Re: slow email validation problems (was reject vs bounce)

2005-09-13 02:58:51


----- Original Message -----
From: "Paul Smith" <paul(_at_)pscs(_dot_)co(_dot_)uk>



I'm thinking of generating '250-please wait' multiline response
lines every 30 seconds or so whilst the message is being processed,
with a final '250 OK' or '550 message rejected because of ...' line.

But, am I being over optimistic expecting SMTP senders to be
able to handle multiline responses any place other than after
an EHLO command?  Also, what happens if the last line of a
multiline response has a different response code to previous
lines (eg "250-" followed by "550 ")?

Paul,

I've tested SMTP client "Keep Alive" ideas using "150-" and it works
perfectly with Outlook.  Example:

    C: DATA
    S: 354 Start mail input; end with <CRLF>.<CRLF>
    S: 150-Please Wait
    S: 150-Please Wait
    S: 150-Please Wait
    S: 150-Please Wait
    S: 250 Message accepted for delivery. (bytes: 2573)
    C: QUIT

I have not tested other Mail sender agents.  But we made sure our mail
sender is ready to support it as well.  I wanted to get a proof of concept
and it is indeed possible.

See my detail report at:

http://www.imc.org/ietf-openproxy/mail-archive/msg03282.html


--
Hector Santos, Santronics Software, Inc.
http://www.santronics.com