If you're having a problem configuring Outlook, you'll have to be more specific regarding which version of Outlook you're using and if applicable, which mode (IMO or C/W). See Help > About, for this info.
There's nothing really special about AT&T requirements. You should have the complete Service Account info available to you from Member Services. Here's some general settings, which I obtained from Member Services' Help:
E-mail and News Settings when dialed up to AT&T Worldnet:
a.. Outgoing Mail (SMTP): mailhost.att.net
b.. Incoming Mail (POP): postoffice.att.net
c.. User name or POP name: This is the first part of your e-mail address; everything before the @
d.. News Server (NNTP): netnews.att.net
e.. Mail Server Type: POP3
E-mail and News Settings when connected with another ISP:
a.. Outgoing Mail (SMTP): imailhost.worldnet.att.net
b.. Incoming Mail (POP): ipostoffice.worldnet.att.net
c.. User name or POP name: This is the first part of your e-mail address; everything before the @
d.. News Server (NNTP): inetnews.worldnet.att.net
e.. Mail Server Type: POP3
f.. Ensure that secure connection (SSL) is enabled and set to port number 995 for POP3.
g.. Ensure that secure connection (SSL) is enabled and set to port number 465 for SMTP.
Hope this helps.
