Account Form:- IMAP/POP
imap.mail.att.net is the incoming mail server.
993 is the incoming mail port.
Yes, encryption is required.
smtp.mail.att.net is the outgoing mail server.
465 is the outgoing mail port.
Username – ATT email address in its entirety
Password – Your ATT email account's current password
These are the ATT mail settings for iPhone 7/8/11, which will enable you to easily customize your account.