Your desktop email application (like Microsoft Outlook or Apple Mail) or mobile email app will use either POP or IMAP to send and receive an email, so be sure to use the correct server and port settings. To update your AT&T email settings today, select ‘File’ then ‘Account Settings.’ Then, choose your AT&T email account and select ‘Change.’ Now, confirm or enter the following IMAP or POP settings: Incoming server: imap.mail.att.net (IMAP) or inbound.att.net (POP3).