Thanks, Stefano. The problem is that Bluehost wants more specific information. “SMTP connect() failed” is too vague. They insist it’s the fault of my email provider.
In the past (last year), TNP generated an error message like “Peer certificate CN=
*.bluehost.com' did not match expected CN=smtp.fastmail.com'” but it doesn’t anymore. I need something so the Bluehost tech support people know *specifically* what to do to fix the problem.
Is there some other test I can run to prove beyond a doubt that Bluehost is blocking the connection and not Fastmail (my email service provider)?