Is the domain @cox.com or is @mc.cox.com also considered a separrate domain. I'm not receiving from the former but am receiving from the latter.
Due to acquisitions, mergers, and other corporate shenanigans it's not clear who does what at AT&T, SBCGlobal, Yahoo, or some undisclosed entity . The web site I log in from is "Currently from AT&T | Yahoo !" Someone in that menage a trois may have an answer so I decided to start at the bottom and work my up to the level of incompetence.
AT&T has their own email system at ATT.com which is different from SBCGlobal.net.