User has to just configure his/her pop3 mail account in AT&T Email. Communicating to a large number of people instantly is possible only by way of forwarding a email, which is delivered instantly. To setting up AT&T Email on windows mail aap.
In Windows Mail, press Windows key + C to access Menu.
Choose Settings > Accounts.
Select Add an account.
Choose Yahoo!.
Full Account Info:
AT&T email address (
YourName@att.net)
Password – type your password
Choose Connect. If you offered the sign in info, your AT&T email will sync with Windows Mail.
Read more -
https://emailscrunch.com/att-email-setup-on-windows-mail-app/