Mail Server Before Working - Now not work!

Hi…
I’ve created a user for email only (info@domain.com) and this work with setting mail.domain.com
Now I’ve created a sub-domains and I’ve applied to this an SSL certificates…
When I try to receive the emails by Outlook, I receive an error…
If I try to open the link mail.domain.com in my browser, they redirect me to subdomain1.domain.com… Why?
Is this the problem…?

Please help me…!