SonicWALL blocking iPad default mail app...

[Rawns]

Has anyone managed to get the default iPad mail app working from behind a SonicWALL box? E-mail via other devices works just fine (and via the 365 portal), and I would have presumed that the only traffic to/from the app would have been mail related so not blocked in any way. I've white-listed the whole of the Apple IP range (17.0.0.1 - 17.255.255.254) so that filtering/DPI does not get in the way but still no joy....

[bald_pig]

Does the sonicwall not have a report to see what it has refused?