First, thanks for a great product! We think that Zimbra is da bomb!
I do have one annoying (in that it is intermittent) problem. I've got remote users who login to the web client. Occasionally they're unable to log in. Sometimes, the login screen doesn't display. They'll refresh several times and it may finally display. Other times the login screen displays and they enter their authentication credentials, but the client doesn't load up. This problem occurs for both the basic and the advanced client, so I don't think it is an Ajax problem.
They've cleared their cache & cookies, but that doesn't seem to help. I've read other similar problems but nothing that I've found matches my scenario. Most of the time, people are able to login without a problem. There doesn't seem to be any networking problems either - they're able to surf to other sites on the web when they experience this problem.
I have seen in the catalina.out file an error message (I've attached one here as catalina.txt). The IP address in the logfile matches the IP of the client trying to connect. I've looked at the archived catalina.out files and see this error all over the place.
Has someone else experienced anything like this?
I'm running Community edition 4.5.5 on Centos 5.