OK this might be the answer?

I am talking purely European experience here........

Maybe Earthlink have given up on providing, and are just marketing............one of you has mindspring, the other verizon, but both are signed up to earthlink?

I have seen it over here with some "store" systems...........they sub-contract the actual servuce provision to someone else?

Another issue is SMTP over a DSL link? Over here you would have to pay for that as a separate issue.......SMTP is for dial-up as a rule.

Just a thought