Exchange 2010 Active Sync

[JoeBloggs]

I currently have an Exchange 2010 server installed and a 2003 Exchange server with legacy mailboxes and we have not yet transfered all accounts to the new Exchange server.

 

Before transfering people over I would like Active Sync to work so I have transfered my account over but cannot get active sync to work on my phone.

 

I have given the email server an external IP from the ISP and OWA works fine through a browser.

 

I have configured SSL in IIS and and the internal and external URL for active sync in the CAS in system manager.

 

But when I try connect with my phone it just says unable to connect.

 

Anyone know any common issues or anything I can try?? Thanks!!