Zimbra Open v. 4.0.3 (Max OS X 10.4 x86)
Thunderbird 18.104.22.168 and 2.0a1 (Mac OS X and WinXP SP2) (IMAP)
Every time Thunderbird checks for new mail it says there is new unread mail, but there actually isn't. It seems like the Inbox is the only folder affected. Even if the Inbox is empty I still get the new mail notification. I tried to delete the account and recreate it, but that doesn't help. Everything else works fine, it's more just an annoyance than a problem. Has anyone else run into this problem?