Open Outlook on your computer, then follow these steps:
1. from the file tab, select Add Account.
2. In the Add New Account window, Select the Manually configure server settings and select next.
3. When asked: Would you like to configure an E-mail Account? Select Yes, then select Next.
4. Select the POP or IMAP radio button, and then select Next.
5. In the User Information section, enter your name and email address.
6. In the Server Information section, For Account Type, select POP3, For Incoming mail server, enter inbound.att.net, For Outgoing mail (SMTP) server, enter outbound.att.net.
7. In the Logon Information section, enter your User Name, your Password, and then select the Remember password checkbox and select More settings.
8. On the Outgoing Server tab, select My outgoing server (SMTP) requires authentication Use same settings as my incoming mail server.
9. On the Advanced tab, Set Incoming server (POP 3) to port 995, Select this checkbox: This server requires a secure connection (SSL), Set Outgoing server (SMTP) to port 465, For Use the following type of encrypted connection, select SSL.
10. Select OK, Next, and then Finish.
But if you are still not able to configure it then contact Att email support by calling 1-800-259-1237. And our expert technician will help you.