This is happening to me.
Same server and IP, also have records in DNS but will not add SSL to mail.
I had to reinstall panel because it needed new hard drive.Tried cyclone200 fix, but not working here.
Going to reinstall to see if I missed anything.
This is the error I get, it seems the same.
Error: DNS record for webmail.mydomain.com doesn’t exist
I’ll reinstall and make a new thread if I still have problems.
I have records for webmail and also one for mail in the panel.
When I saw “I have an A record for mail and webmail which points to my IP in the panel”
I thought I might have the same error.