There can be many possible issues in case your AT&T email not working on iPhone devices. Let’s find out the reason of the same:
· Initially, you need to check an internet connection on your iPhone.
· After that check the settings of At& T, IMAP, incoming mail server, outgoing port, and authentication port are connected or not
· Other possible reason is that your account gets deleted by AT&T.
· If the services are disconnected from AT&T, then your email will no longer work on iPhone device.
Additional assistance can be taken by dialing a toll-free phone number of Yahoo At&T Support .