Possibly related issue, i can't get all my Iphone end users to activesync with my Exchange server. Not sure if its related but that's another issue with apple products I'm having on my network at this time. With activesync i was able to verify the server from the Iphone but not connect to the email folder.
Below is script from the Itunes Store diagnostic
Connection attempt to Apple web site was successful.
Connection attempt to iTunes Store was successful.
Secure connection attempt to iTunes Store was successful.
Secure connection attempt to iPhone activation server was successful.
Last successful store access was 2010-08-25 13:34:08.