After using the sync function on the Zimbra Desktop from Yahoo Email and Yahoo Business Email I discovered that the Inbox and Sent folder were missing emails. There were two methods used to check the sync results.
Note: Made sure Zimbra Desktop "View" used Message. Not Conversation.
1. Change the date sort by from newest to oldest for the Inbox and Sent folders.
- When this was done Zimbra Desktop displayed email dated August 2010. However, the Yahaoo page show the oldest as 2009.
2. Compared the email/message count between Zimbra Desktop and Yahoo.
- When this was done, the count showed that Zimbra Desktop was missing email messages.