So, fine, I know that Cox blocks SMTP port 25 except when it comes to their own servers (which I think is just stupid, but whatever). So I built an additional SMTP receive connector on our mail server for my one Cox telecommuter, and it uses port 26 instead. But he tells me that he still can't send from his Cox connection.
Does anyone currently use port 26 to connect to a non-Cox SMTP server. Or use any other port that works, for that matter?
And, no, I'm afraid using Cox servers with his Cox ID to authenticate, while spoofing his own corporate email address is only a partial answer - many of the systems he'll be sending mail to use SPF to verify the identity of a sender, and will reject email that doesn't trace back to our server.
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