I had this issue some time ago and though that issuing a Mail SSL fixed it, though it didn’t and it’s weird.
I tried to see with checktls about a domain of mine biomass-energy.gr. But the reply I have comes from another domain (which is the last domain I manually issued the Mail SSL!!!)
But now from a contact form, if I use domain (mail.domain.com) is not working. I have to use the Cyberpanel’s DNS name to work.
Also sending an email with these settings I get an issue with this:
The IP address sending this message does not 550-5.7.25 have a PTR record setup, or the corresponding forward DNS entry does 550-5.7.25 not point to the sending IP. As a policy, Gmail does not accept 550-5.7.25 messages from IPs with missing PTR records.
Yes it is right now the right one. The mail server is CyberPanel’s domain now and the PTR record too.
Running this
postmap -F hash:/etc/postfix/vmail_ssl.map
fixed the issue with the Cert FAIL in checktls. But now if I want any service (Wordpress contact form for example) to use the email, I have to use the cyberpaneldns.com as SMTP server and I cannot use the mail.websitewithcontactform.com.