bloop.email
IMAP settings

AT&T IMAP and SMTP settings

The server settings to add AT&T to any mail app, for addresses ending in @att.net, @sbcglobal.net, @bellsouth.net, @ameritech.net, @pacbell.net, @prodigy.net, @swbell.net, @snet.net, @flash.net, @nvbell.net, @currently.com or @wans.net.

Incoming mail (IMAP)
Serverimap.mail.att.net
Port993
SecuritySSL/TLS
Outgoing mail (SMTP)
Serversmtp.mail.att.net
Port465
SecuritySSL/TLS
Sign-in
UsernameYour full AT&T email address
PasswordA secure mail key from your AT&T account, not your regular password.

From AT&T Support: POP3 and IMAP email settings. Check there if something has changed.

Before you start

Use AT&T in a native Mac app

Bloop.email works with any IMAP account. Enter these settings once, and AT&T sits next to your other inboxes, with trackers blocked and nothing between your Mac and your provider.