Outlook fails to login or retrieve emails after a server move. This is due to the SSL certificate on the new server confusing Outlook. This is especially important when the mail server name used in Outlook doesn’t change during the move. The solution is to reset or regenerate the email services certificates on the new server then restart outlook. Or you could also delete the certificate pertaining to the host name used in outlook (ex: mail.vpslux.com). If you are using cPanel on the server, you can reset the SSL certificate via WHM -> Manage Service SSL Certificates.
That’s all folks!