RES: Possible IMAP IDLE bug in Dovecot 2.2.18 and 2.2.25

[Cleber @ Listas]

Hello Timo,

The capability result from dovecot and Smartermail:

Dovecot:
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE
STARTTLS AUTH=PLAIN AUTH=LOGIN] Dovecot ready.

Smartermail:
* CAPABILITY IMAP4rev1 AUTH=CRAM-MD5 UIDPLUS QUOTA XLIST CHILDREN

If I connect directly to Smartermail the Outlook don't send the IDLE command
(only NOOP, because the Smartermail don't send the IDLE in CAPABILITY).
But, it's with time interval better than from Dovecot (a lot in same second)

10:25:11 [201.74.248.186][57965505] connected at 24/08/2016 10:25:11
10:25:11 [201.74.248.186][57965505] command: 1ope CAPABILITY
10:25:11 [201.74.248.186][57965505] command: 9mv2 LOGIN "myaccount at mydomain"
XXXX
10:25:11 [201.74.248.186][57965505] myaccount at mydomain logged in
10:25:11 [201.74.248.186][57965505] command: rvzd LSUB "" "*"
10:25:11 [201.74.248.186][57965505] command: rh9g SELECT "INBOX"
10:25:11 [201.74.248.186][57965505] response: * 919 EXISTS
10:25:11 [201.74.248.186][57965505] response: * 0 RECENT
10:25:11 [201.74.248.186][57965505] response: * OK [UNSEEN 904] Message 904
is first unseen
10:25:11 [201.74.248.186][57965505] response: * OK [UIDVALIDITY 1] UIDs
valid
10:25:11 [201.74.248.186][57965505] response: * OK [UIDNEXT 26849] Predicted
next UID
10:25:11 [201.74.248.186][57965505] response: * FLAGS (\Answered \Flagged
\Deleted \Seen \Draft)
10:25:11 [201.74.248.186][57965505] response: * OK [PERMANENTFLAGS
(\Answered \Flagged \Deleted \Seen \Draft)]
10:25:11 [201.74.248.186][57965505] response: rh9g OK [READ-WRITE] SELECT
completed
10:25:11 [201.74.248.186][57965505] command: ve5e FETCH 919 (UID)
10:25:11 [201.74.248.186][57965505] command: 8ixa UID FETCH 1:26848 (UID
FLAGS)
10:25:14 [201.74.248.186][57965505] command: t874 UID STORE 26846
+FLAGS.SILENT (\Seen)
10:26:32 [201.74.248.186][57965505] command: rmcb NOOP
10:26:32 [201.74.248.186][57965505] response: rmcb OK NOOP completed
10:28:39 [201.74.248.186][57965505] command: qs5n NOOP
10:28:39 [201.74.248.186][57965505] response: qs5n OK NOOP Completed
10:31:01 [201.74.248.186][57965505] command: k9v0 NOOP
10:31:01 [201.74.248.186][57965505] response: k9v0 OK NOOP completed
10:33:01 [201.74.248.186][57965505] command: vw8w NOOP
10:33:01 [201.74.248.186][57965505] response: vw8w OK NOOP completed
10:35:01 [201.74.248.186][57965505] command: qhag NOOP
10:35:01 [201.74.248.186][57965505] response: qhag OK NOOP completed
10:37:01 [201.74.248.186][57965505] command: so7b NOOP
10:37:01 [201.74.248.186][57965505] response: so7b OK NOOP completed
10:39:01 [201.74.248.186][57965505] command: wclw NOOP
10:39:01 [201.74.248.186][57965505] response: wclw OK NOOP completed
10:39:36 [201.74.248.186][13534103] disconnected at 24/08/2016 10:39:36





-----Mensagem original-----
De: dovecot [mailto:dovecot-bounces at dovecot.org] Em nome de Timo Sirainen
Enviada em: quarta-feira, 24 de agosto de 2016 06:49
Para: cleber-listas at inetweb.com.br
Cc: dovecot at dovecot.org
Assunto: Re: Possible IMAP IDLE bug in Dovecot 2.2.18 and 2.2.25

On 23 Aug 2016, at 15:08, cleber-listas at inetweb.com.br wrote:
> 
> Hello Guys,
> I guess that I found a bug in Dovecot 2.2.18 and 2.2.25 versions. The 
> problem it's when I try to connect in a Dovecot used a proxy to 
> another e-mail server (in our case it's a Smartermail Server) the 
> DoveCot send a lot of IDLE commands to the destination server. With 
> that, the LOG files grow and grow and grow :(
> 
> I make a test with 1 connection only and if you see the log file in 
> the same second the dovecot send 25, 40 IDLE commands. But, when I 
> disconnect the client (outlook 2013) the dovecot continue to send the 
> IDLE command for some seconds.

After login Dovecot proxy no longer understands anything about the traffic.
It simply keeps proxying the IMAP traffic between the client and server. So
Dovecot isn't the one generating the IDLE commands, it's Outlook.

> If I try to connect directly to Smartermail with Outlook this don't 
> occurrs.

That is stranger then. Maybe it has something to do with having a different
CAPABILITY response. You could try setting imap_capability setting to same
as what Smartermail announces. Other than that I can't really think of
anything specific that you could do or we could fix on Dovecot code.