Users on Exchange 2013 cannot access mailboxes on the VPN

Hi,

We are running coexistence for Exchange 2007 SP3 and 2103 CU13 and any staff moved to Exchange 2013 cannot access their mailboxes in Outlook 2010 while on the VPN.  It never connects just times out.  We have added the IPs for the new Ex2013 servers to our existing "Outlook Ports" Firewall thinking this would be all, but no dice.

The "Outlook Ports" rule currently configured in the FW contains the following ports:

TCP  135

TCP  6001-6002

TCP  63005-63006

TCP  88

TCP  443

TCP  389

Do we need to add more ports, or is it a setting on the mailbox when moved to Exchange 2013?

Thanks