Networks

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

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.

are you connecting to the mail through a server or just a normal router ?