[Dovecot] very frequent disconnections

[Dan Christensen]

Timo Sirainen <tss at iki.fi> writes:

> On Wed, 2009-10-07 at 20:55 -0400, Dan Christensen wrote:
>> Oct  7 20:19:40 jdc dovecot: IMAP(jdc): Connection closed bytes=303/1423
>> Oct  7 20:44:00 jdc dovecot: IMAP(jdc): Disconnected in APPEND bytes=1081/1965
>
> The connection just got closed from Dovecot's point of view.
>
> Have you tried without SSL?

The very frequent dropped connections don't happen if I don't use TLS.
To summarize:

- they happen with TLS to port 143
- they don't happen with a plain connection to port 143
- they don't happen with a TLS connection to port 11143
- they don't happen if I connect using
    ssh jdc.math.uwo.ca dovecot --exec-mail imap

Very strange.  I can trigger the drop 100% of the time by copying 20 or
30 messages from a local folder to a remote imap folder.

> Anyway I can't think of anything besides some weird network issue or
> maybe some firewall/antivirus in the middle.

Could be.  But now it's clear that it's not affecting all traffic
to port 143, only tls traffic.  Weird.

> Some clients also support "imap over ssh", you could try that. Basically
> use "ssh server dovecot --exec-mail imap" as the command.

That works well and is also quite fast to connect, so I'll probably
stick with it.

Thanks for the help,

Dan