Setting up email via web-interface not working SOLVED

I’m seeing this in the error:

Failed to send email: System.IO.IOException: The authentication or decryption has failed.
→ System.IO.IOException: The authentication or decryption has failed.
→ Mono.Security.Protocol.Tls.TlsException: Invalid certificate received from server.

Combined with you running as a service has me wondering if you’re experiencing some Linux flavor of the TLS error mentioned here.

Oh, and I’m not finding it now (and it may not apply) but there are known issues with mono not including “standard” certificate information by default. If you think that might be the case, let me know and I’ll try looking again.