We have the same issue too. However once you enter the passwords again and possibly again and again ;-) then it does actually functionally work. Though it is irritating and pointlessly time consuming, as I havent yet found a way of using the Zimbra desktop for more than one email account I need some other full offline client.
There seems to always be something that gets in the way with the Linux or OSS desktop that makes it lumpy. Still I prefer the lumps to proprietary traps!
K |