Mail not sending or receiving Exchange email

I just upgraded from an iPad mini 2 to an iPad Air 2. I also have an iPhone 5s. All devices run iOS 8.3. The Mail app on the mini and the iPhone handled all my accounts flawlessly - Gmail, Exchange, and iCloud. When I set up the Air, the Gmail and iCloud accounts work in Mail, but I can't send or receive emails on my Exchange account. I checked all the settings and compared them to the settings on my iPhone. Identical. I tried deleting the Exchange account and then setting it up again. After I enter all the info in the Mail settings, I get all the green check marks when I verify. Still, I can't send or receive emails with my Exchange account. And ideas as to what I might have missed or where I went wrong? Thanks!