Can't validate the smtp server on Mailwizz (error:1408F10B:SSL routines:ssl3_get_record:wrong version number)

SMTP Servers
#1

I built my server on contabo using Webmin and installed mailwizz on the root on the same VPS, but when I add my SMTP to Mailwizz and want to validate it I keep getting this error below. I even tried switching between SSL and tls and nothing changed.

Connection could not be established with host mydomain.com :stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:
error:1408F10B:SSL routines:ssl3_get_record:wrong version number
Log data:
++ Starting Swift_SmtpTransport
!! Connection could not be established with host mydomain.com :stream_socket_client(): SSL operation failed with code 1. OpenSSL Error messages:
error:1408F10B:SSL routines:ssl3_get_record:wrong version number (code: 0)
#2

Use checktls.com to verify your TLS.
If it’s ok, then test your smtp credentials at SMTP Test Tool

Thanks