You might want to use DigWebInterface to check your MX records. Type in your domain, pick type MX and select ALL in the name servers. This will show the MX results from several different public DNS servers like Google and Cloudflare.

You should also do the Authoritative nameserver option as that will show if the DNS servers hosting your domain are providing the correct information.


After looking at your email attachment, I don't see any issues with your DNS. I think something is wrong with the DNS on the senders side.