Exchange 2010 iApp problems with Mac OSX 10.8 Mail App

We have a pair of LTM's (11.2.1 807.0) running the following version of the Exchange 1010 iApp:

f5.microsoft_exchange_2010_2013_vas.v1.2.0rc1

Clients who use OSX 10.8 with the Apple Mail app are not able to access their Exchange mailboxes. I believe the app uses EWS to connect to the user's mailbox. This is the error that the client shows:

The error initially states “The server returned the error: Connections to host exchange.domain.com on the default ports failed”. Opening the connection doctor, it says it could not connect to the Exchange server and suggests turning off SSL.

We previously had a setup on 10.x running an older version of the iApp did not have this problem. OL for Mac connects fine (although it probably uses MAPI).

Any ideas?

Thanks,

Josh