dovecot - Jun 2011 - Dovecot 2.0.13 problem with LMTP

Hello,

we have dovecot 2.0.13 installed in our RHEL5 servers. We use dovecot as a lmtp
proxy on the front end mail relays and dovecot for back end lmtp/pop/imap. All
our servers have RHEL5.6 64-bit and dovecot 2.0.13 installed, and the back end
has also an ext3 mbox file-system mounted.

Sometimes we have mails that get stuck on our postfix queue with the following
error: Remote server not answering (timeout in DATA input) (in reply to end of
DATA command)

In our logs we only see the fact that the connection times out after 1 minute
and gets disconnected:

Jun 22 11:56:53 back-end dovecot: lmtp(3256): Connect from a.b.c.d
Jun 22 11:57:53 back-end dovecot: lmtp(3256): Disconnect from a.b.c.d:
Connection closed

Jun 22 11:56:53 front-end dovecot: lmtp(16397): Connect from a.b.c.d
Jun 22 11:57:53 front-end dovecot: lmtp(16397): Disconnect from a.b.c.d:
Disconnected for inactivity

We've tried to recalculate the mbox quota using "doveadm quota recalc
-n ..." command and flushed our mail queue, but the mail still gets stuck
on the postfix queue with the same error.

It doesn't happen for every single mail, it's random.

I'm attaching the output of dovecot -n for both servers.

Can you please help us?

Regards

CINZIA INNOCENZI
Technical Consulting
HP Enterprise Services
Telephone +39 06.6542.5758
Email cinzia.innocenzi at hp.com<mailto:cinzia.innocenzi at hp.com>
Via Achille Campanile, 85 / Rome, Italy  00143

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if u already didnt, try setting 'mail_debug=yes' in config.

-- 
Simone Caruso
IT Consultant
p.iva: 03045250838

On Wed, 2011-06-22 at 10:31 +0000, Innocenzi, Cinzia
wrote:
> Hello,
> 
> we have dovecot 2.0.13 installed in our RHEL5 servers. We use dovecot
> as a lmtp proxy on the front end mail relays and dovecot for back end
> lmtp/pop/imap. All our servers have RHEL5.6 64-bit and dovecot 2.0.13
> installed, and the back end has also an ext3 mbox file-system mounted.
> 
> Sometimes we have mails that get stuck on our postfix queue with the
> following error: Remote server not answering (timeout in DATA input)
> (in reply to end of DATA command)
..
> It doesn't happen for every single mail, it's random.
My guess is there's a bug somewhere in the LMTP proxy code. It's a bit
annoyingly complex code.. Do you see this happening when proxying only a
single mail (one RCPT TO per DATA, not multiple)?

And I would guess that when attempting to deliver the same mail again it
works fine (at least in a few tries)?