My apologies then, I thought that it was some subset of features within the MS 365, which I obviously know nothing about.
IF it is working on the phone and the iPod, I assume that it's not a corrupt email or attachment causing the problem, or it would be causing the problem on all devices. Without knowing if you are running the same iOS on each device, it could be iOS specific, but I'm guessing you're running iOS 8.1.2 on all three.
Have you tried closing all apps on the iPad, reset the device and then try again? Or something else that helps at times is to reset all settings. Settings>General>Reset>Reset all settings. No data is lost, but all of your device settings have to be entered again and that takes a little time to do.