The trouble appears when I attempt to configure a client account in Mail.app on my Mac. For the POP server name, I enter my VPS? ?45.56.81.181", because public DNS is still pointing to my existing host. I set the account to use the Apple TLS certificate, and then click to save this new account info. Before saving, Mail.app checks my entries by attempting to log in. The result is: ?The identify of server 45.56.81.181 cannot be verified. The certificate for this server is invalid.?
Well, yes, that's what you would expect. You've told your mail client to connect to "45.56.81.181", the client starts the SSL negotiation and finds the certificate is made out for "sheepsystems.com", and your mail client complains about the mismatch (a possible MITM attack). This is what you want SSL enabled system to do.
Since 45.56.81.181 does not map to "sheepsystems.com" yet, you can short-circuit DNS and add a direct mapping to your Mac by adding this to /etc/hosts:
45.56.81.181 sheepsystems.comthen reconfiguring your mail client to use the server "sheepsystems.com". This will appease the SSL constraint.
appear in /var/log/mail.log [2].
Don't know what this is about -- probably your Mac bailing out on authentication.
Joseph Tam jtam.home@gmail.com