> You actually think that the best answer to a network engineering problem is to make legal threats at third party ISPs? If the remote mailserver is explicitly

> You actually think that the best answer to a network engineering problem is to make legal threats at third party ISPs? If the remote mailserver is explicitly bouncing your mails, it's not a network engineering problem. If you're able to complete a TCP 3 way handshake, it's not a network engineering problem. If you're being prevented from completing a TCP 3 way handshake because of a filter list on the MX server, it's not a network engineering problem. Admittedly, you can't tell that one without asking a network engineer (on the remote network) to validate that for you, or asking the application owner to advise. Contrary to popular advice (thanks MSFT), you probably shouldn't contact your network administrator. We probably have priv 15, but we dont necessarily have root.