I am running Outlook for mac  2011 version 14.3.9 on OSX 10.9. Microsoft Exchange Client server version is 8.3.83.0
Server operating system version is Microsoft Windows NT 6.1.7601 Service Pack 1

My mail is accessible on my Iphone and on webmail, but is not appearing in Outlook for Mac 2011. Folders are appearing and I am able to send email, but not receive. I am not able to see my calendar nor other calendars. When synching, the system tries to load some 4500 emails and goes on for about an hour, finishes- but nothing appears in the inbox.

Based on other posts, I have tried the following without success:

Toggling the "Show in Groups" command
Determining the size of the identity- around 450 MB, I have approx. 600GB available.
Emptying the Outlook cache 
Backing up identity, rebuilding identity and restarting
Creating a new identity- when connecting to Exchange I get an error message saying: "Account could not be added. Note that Outlook 2011 requires Exchange Server 2007 SP1 update rollup 4 or later"

I have seen that other people have had success by reverting to Outlook for mac 2011 version 14.0.0. Should I try that? Or do I need to update the Exchange client server version?
Do you have other workarounds or a fix?

Thanks,

T. Flyen