Just so nobody is confused about SBCGlobal, AT&T and Yahoo. Back in the day, SBCGlobal was an Internet provider but after rebranding, mergers and selling to other companies, there is no more SBCGlobal.net.
However, its users can still use their defunct email accounts by logging in through special AT&T or Yahoo portals...which were part of said mergers and selling.
For example, if Cox finally terminates all email service, its current contractor may allow us to continue using our email addresses with the Cox domain. Then it would probably become Cox Email Service "Currently from [whomever the contractor]."