Emails are not working, Pl. Help

My emails are not working and A record and MX record changes automatically. So I remove my site from cloudflare and add it again.
Now A and MX record point to correct mail providers IP. I also checked in MXtoolbox and dnschecker tool.

But when email send to me, it gets following messages back 0-

Message not delivered

Your message couldn’t be delivered to [email protected]{redacted} because the remote server is misconfigured. See technical details below for more information.

For your reference, here is the screenshot -

Please help me.

The DNS Setup seems to be ok.
But anyway I would never host MailServer and WebServer on the same Server but thats your decision.

Pls have a look at your Mailserver on your Server it he is configured right, or provide some more infos and better Error Logs so we can help you