Outlook 2003 dropping IMAP connection after 5.0 GA upgrade

[Mark Daniel]

Heya all,
I'm having an issue ever since upgrading our ZCS 4.5.9 server (on Mac OS X Server 10.4.10) to the 5.0 GA release. It seems that Outlook 2003 clients (accessing via IMAP, previously working flawlessly) are having their IMAP connections dropped prematurely by the Zimbra server whenever viewing messages with attachments over about 3MB. However, this does not seem to affect Thunderbird or Apple Mail clients.
When attempting to view these messages, the Outlook client nearly immediately displays a message saying that the item could not be viewed because the server has dropped the connection. "This may be cause by the connection having been left idle for too long," or something to that effect. The server appears to be running flawlessly otherwise...

Any ideas?

[Mark Daniel]

This is killing my users... any ideas, oh wonderful Zimbra community members?

[dkarp]

Are you using the IMAP proxy?

[Mark Daniel]

Negative... don't even have it installed. The part that's confusing me is that this only affects Outlook clients, nothing else (not Apple Mail, Thunderbird, etc).

[dkarp]

Can you turn on protocol-level IMAP logging and post the chatter between client and server when Outlook 2003 tries to fetch such an attachment?

[Mark Daniel]

I'd love to! How do I do that? Wikidigging now...

[Mark Daniel]

Ok, here's what I get in mailbox.log when the user selects the message in Outlook 2003:

2008-01-04 12:17:32,436 INFO  [ImapServer-920] [] imap - [192.168.1.117] connected
2008-01-04 12:17:33,677 INFO  [ImapServer-920] [name=user@domain.com;ip=192.168.1.117;] imap - user user@domain.com authenticated, mechanism=login
2008-01-04 12:17:33,682 INFO  [ImapServer-920] [name=user@domain.com;ip=192.168.1.117;] imap - selected folder HOUR 02-08/Margot
2008-01-04 12:17:35,091 INFO  [ImapServer-920] [] ProtocolHandler - Exception occurred while handling connection
java.lang.IllegalArgumentException: negative skip length
	at java.util.zip.InflaterInputStream.skip(InflaterInputStream.java:174)
	at com.zimbra.common.util.ByteUtil$SegmentInputStream.create(ByteUtil.java:651)
	at com.zimbra.cs.imap.ImapPartSpecifier.writeMessage(ImapPartSpecifier.java:110)
	at com.zimbra.cs.imap.ImapHandler.fetch(ImapHandler.java:2930)
	at com.zimbra.cs.imap.ImapHandler.doFETCH(ImapHandler.java:2789)
	at com.zimbra.cs.imap.ImapHandler.executeRequest(ImapHandler.java:412)
	at com.zimbra.cs.imap.TcpImapHandler.processCommand(TcpImapHandler.java:151)
	at com.zimbra.cs.tcpserver.ProtocolHandler.processConnection(ProtocolHandler.java:160)
	at com.zimbra.cs.tcpserver.ProtocolHandler.run(ProtocolHandler.java:128)
	at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Worker.run(Unknown Source)
	at java.lang.Thread.run(Thread.java:613)
2008-01-04 12:17:35,107 INFO  [ImapServer-920] [] ProtocolHandler - Handler exiting normally
2008-01-04 12:17:35,419 INFO  [IndexWritersSweeperThread] [] index - open index writers sweep: before=8, closed=0, after=8 (0ms)

[dkarp]

Looks like a bug in the Zimbra server. Let me see if I can repro on my box... (Filed it as Bug 23445 - Outlook 2003 dropping IMAP connection after 5.0 GA upgrade)