Hello David,
What version are you running?
Your description sounds a little like what we implemented in 6.0.8 to protect against bad Mail.app IMAP behavior:
If the problem is not similar to this one, I'd suggest opening a new case. In ZCS7, the number of IMAP sessions allowed by default is 15 (15 concurrent IMAP connections). In ZCS5, it may have been 5, so perhaps that is what you're running into. ZCS 7 and later:
zimbra_session_limit_imap = 15 # IMAP
zimbra_session_limit_soap = 5 # SOAP
zimbra_session_limit_sync = 5 # ActiveSync
Hope this helps,
Sincerely,
-thom
From: "David Blank-Edelman" <dnb@ccs.neu.edu>
To: "Helpful Zimbra Admins" <zimbra-hied-admins@sfu.ca>
Sent: Tuesday, August 28, 2012 2:15:03 PM
Subject: multiple Mail.app instances fighting
Hi-
Just curious if other people have seen this behavior: we've noticed with a few users that leave their work and home machines on that their two OSX Mail.app instances "fight" over zimbra. This manifests as the two instances basically doing repeated IMAP authentications to our server again and again (so e.g. we had one user whose lines in auth.log were 87% of that logs contents). Apparently you can see in the activity window tons of "Checking capabilities" when this happens.
We're running a bit of an ancient version of Zimbra here (hope to upgrade after we get past the beginning of the year maelstrom), so perhaps this isn't as much of a problem with later versions. It is mostly a nuisance (the users can work fine) that fills logs, but beyond that not a real problem.
Is this just us, or have you seen it too and found a way to deal with it?
-- dNb