We have hosted Exchange email and find that Outlook 2011 (for Mac) has numerous synchronization issues including;

1. Multiple copies of a single email/contact all with the same details (date/time stamp) -- have seen 2-6 copies 

  -Took a 6GB email account to close to 20GB

2. Hundreds of Email read and filed into folders never synchronized with Exchange

  -Evidenced in OWA, a Windows computer with Outlook, and a new identity created in Outlook 2011

3. Old meeting requests/remidners intermittently pop-up 

4. Recurring pin wheel and delayed email

5. Sync errors (Outlook 2011)

Any real fix or solution?

Web search suggests that Apple points to Microsoft and Microsoft seems to point to Apple.  Meanwhile, some company employees have set aside thier Mac rather than dealing with the headaches. (Score for Windows)

Scouring the web, we've implemented some best practices found here http://www.valiant-ny.com/2012/10/outlook-2011-for-mac-and-exchange-sync-issues/

We've implemented Best Practices Such As:

 Keep account under 3GB
 Keep Inbox and Sent folders under 4000 items
 Utilize folders and place under main account – not Inbox
 Perform major email moves on Outlook Web Access (web mail) Perform major email moves one process at a time allowing synchronization time
 Archive using Outlook for Windows and import into Outlook for Mac
 Keep archive files limited to 2GB maximum
 Set Outlook to download headers only unless offline access is needed
 Exit Outlook cleanly versus minimizing and allowing the computer to sleep/hibernate

Thanks