MBOX-Line: From dave at cridland.net  Mon Mar 12 14:28:45 2007
To: imap-protocol@u.washington.edu
From: Dave Cridland <dave@cridland.net>
Date: Fri Jun  8 12:34:38 2018
Subject: [Imap-protocol] how long can APPEND take?
In-Reply-To: <07Mar12.121950pst."57996"@synergy1.parc.xerox.com>
References: <07Mar12.121950pst."57996"@synergy1.parc.xerox.com>
Message-ID: <18599.1173734925.056533@peirce.dave.cridland.net>

On Mon Mar 12 13:19:45 2007, Bill Janssen wrote:
> Due to my current back-end architecture, adding a mail message to a
> folder can take a considerable amount of time, up to 10 minutes or 
> so,
> depending on whether attachment content has to be OCR'ed for the
> Lucene index.  It looks to me as if the semantics of APPEND, this 
> may
> be unacceptable:
> 
>       If the mailbox is currently selected, the normal new message
>       actions SHOULD occur.  Specifically, the server SHOULD notify 
> the
>       client immediately via an untagged EXISTS response.
> 
> Nothing's going to happen "immediately".  Of course, I presume that
> "immediately" in this context means, "whenever the server first
> notices the new message".  I can hang the connection for N minutes 
> or
> so till the result of the attempted message incorporation is known;
> the client can always open another connection in the meantime.  Then
> I can respond once the APPEND is complete.
> 
> Comments?

Yes. :-)

An APPEND should never take more than a couple of seconds. There's no 
point in scanning images at this point, instead, have your system 
append the message instantly, and then scan through the messages 
later to classify them. They're not going to be spam, since they've 
been explicitly added by the user.

For delivery, it's different, but for IMAP, a client finding an 
APPEND hanging for more than a few seconds isn't going to wait 
patiently or open a new connection, it'll most likely hang, or cut 
the connection and make a new one.

FWIW, users expect that a delivery is pretty well instant too, in 
fact, so I think you're doomed to failure here.

Dave.
-- 
Dave Cridland - mailto:dave@cridland.net - xmpp:dwd@jabber.org
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