I am having the exact same problem.
I am also on a Mac - Macbook Pro, Intel Core Duo, OS X Tiger 10.5.5.
I've completely uninstalled and reinstalled Zimbra. When setting up my Yahoo Mail account, it will download my mail, but then it won't send/receive or sync. I get a message saying
"Status: Authentication failed with account "_____@yahoo.com". Please go to Account Setup for more information."
When I go to Account Setup, I see the following message:
"Password may have changed. Please go to edit screen of Account Setup to revalidate settings."
I have setup my Yahoo Mail account in Zimbra to sync contacts and calendar as well. I am using the new Yahoo Calendar beta.
Please help!
