I have no relation, but as a mail server operator I can say that I wouldn't be surprised if this is actually a TLS version mismatch or intolerance problem. I would suggest ensuring that both ends support TLS 1.0, 1.1, and 1.2 and use version tolerant TLS implementations. Next on the short list would be not having compatible cyphers between the two servers. Either way, since the error was a 403 error, the expected behavior would be to queue and retry in plain text; Sounds like a broken MTA implementation or misconfiguration if the sending servers do not revert to plain text. --Blake Jay Ashworth wrote on 6/4/2015 11:15 AM:
Anyone on the list who does outbound delivery for Verizon (which I think is actually Superpages)? A client has smart-hosted outbounds to *one* of his customers bouncing suddenly with
Deferred: 403 4.7.0 TLS handshake failed.
*My* inclination is to think that a cert expired somewhere, but his non-tech contact there tells him that the tech people think things are ok.
I'm trying to get a mailer log fragment from them.
Cheers, -- jra