said by Forosnai:Sounds like he imported his yahoo ID over as a paid ATT account. When that is done they are exactly the same, but all the password and security stuff behind ATT's walled garden is done as xxx@att.net.
Sounds a bit different from what I remember. Back when I was a customer, and before SBC bought AT&T, I was able to "merge" a free Yahoo! Mail account with the SBC account; but the Yahoo! account did not become a sub-account, it became an alias to whichever sub account I merged it with.
Edit to demonstrate:
Merged accounts.
Although the same user name was used for both, I have also merged with different user names. I have not recently played with account management; not since leaving AT&T.