My company just switched our mail server to Zimbra, and I am seeing some very strange behavior in my preferred email client, kmail on Kubuntu. (I am using KDE 4.x)

I am seeing very strange behavior and suspect that I have something configured wrong on one side or the other.

There are two main symptoms:

First, kmail seems to download unread messages from the server repeatedly. I sometimes end up with as many as 15 or 20 copies of the same message. I suspect that kmail is not noticing that it has downloaded the email until it has been read.

Second, if I am in another folder and the kmail folder summary is showing, for example, 38 messages with 6 unread, and I click on that folder entry, the counts drop briefly to 0 and 17 and messages disappear from the message list displayed. Things thrash for a while, with numbers bouncing around and messages appearing and disappearing, then eventually settle back to the original values, with the new messages visible again in the messages list.

Are there settings I need to tweak in either kmail or zimbra or both to get better behavior?

In the past I have generally configured my email to delete messages from the server when they are downloaded. I'm willing to change that, if necessary, but it is pretty clear that messages are NOT being deleted at download on the server, or they would be available to download repeatedly.