siimonsander The issue could be that the hostname is rubriik.ee and not www.rubriik.ee.
I also suggest you use the TLS option from that provider.
So settings would likely be:
Host: rubriik.ee
Port: 465
Encryption: tls
The domain name is indeed strange. Maybe it's a mistake and it should be mail.rubriik.ee for TLS option as well ? Though it's not that strange if it's a shared hosting with everything on the same box and no proxy servers.
By the way I just tested and the mail subdomain does not resolve at all, so I doubt it would work with it. Also www and bare domain both resolve to same IP so it should give the same result whichever one is used.
What's the hosting provider ? Did you manually alter any DNS records ?
Also did you try without @rubriik.ee for the username ? Sometimes these shared hosting do not actually prepend the domain to the username.
The log files might give a useful SMTP error when trying to send email.
