Installed fine but then the confusion began...
I installed beta 3 yesterday and set up to load mail from Yahoo Business Mail and Gmail. Gmail loaded and continues to stay updated just fine. Yahoo Business Mail displayed all my folders in Zimbra but no email seemed to load. So I poked around the forum and someone suggested that Zimbra requires an account to be IMAP enabled to load Yahoo Business Mail.
So I went back to Zimbra and found that one of my folders for Yahoo Business mail had loaded 330 messages totalling 60Mb. If IMAP was necessary (and I had not enabled it), why did 60Mb of messages load into one of my Zimbra folders from my Yahoo Business Mail?
I do not see anything in the Zimbra interface that indicates Zimbra is updating or how much has been updated. While Gmail seems to be updated appropriately and one of 11 folders for Yahoo Business Mail seems to be updated, all I can conclude at this point is that the version of Zimbra I am using is throttled for extremely slow updating from Yahoo Business Mail. But that does not explain why 1280 messages from my Gmail to Zimbra have loaded and update appropriately within minutes.
Why might my Zimbra installation not upload and update all messages from Yahoo Business Mail? If nothing worked, I would try to figure out about the IMAP stuff. Since my current installation works, albeit only partially, I am not sure what to do next to get my Yahoo Business Mail to upload completely and stay synchronized.
Just took a look at my mailbox.log file which is at 17.8 Mb so things are happening. I can see the record of successful transfer of Yahoo Business Mail messages.