+ 0 Votes These are your E Mail User Name and Password that is being asked for OH Smeg 1 year ago Not your Network User Name & Password. The E Mail Password is generally your E Mail Address something like JohnSmith@xyz.com. You also need to remember that even if you have the correct E Mail User Name & Password that these are Case Sensitive so if you are using a capital and everything is in lower case then it's not going to work. The same applies if you are using Lower Case and you need Capitals in at least part of the E Mail Address or Password. Col + 0 Votes Reponse To Answer basemkhawaja 1 year ago I am not sure , I use a Cisco Dual Band Router, But ATandT is my ISP, I can check my email through mail.yahoo.com as well, but i prefer OUTLOOK which i have been using for years Thanks + 0 Votes Try webmail to confirm user name and password actually works. Craigceg 1 year ago Have you gone to AT&T's webmail and successfully logged in using the same user name and password you are trying to put in Outlook? If you get the same error when logging in to webmail, then you do not have the correct user name and password combination. If you can successfuly login to webmail and those credentials do not work in Outlook then it is usually a temporary problem with the AT&T/Yahoo email servers. I have the same problem a couple times a month, where Outlook asks for user name and password even though nothing has changed on my end and I can log in to webmail. If you wait a little while it usually resolves itself. + 0 Votes conection shane s 1 year ago are you connecting to the mail through a server or just a normal router ?