That is a good solution.
But i have a case. How about if i would like to keep on the other registrar the domain, the web hosting and only use DH for email hosting?
In my mind i needed to change only the MX record in the DNS configuration on the other registrar hosting and point it to the IP adress of DH. It seems to work fine but only in outbond. I can send email from DH but can not receive from outside. Other email servers are getting the following error:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain mydomain.com by mail.mydomain.com. [188.8.131.52].
The error that the other server returned was:
554 5.7.1 : Client host rejected: Access denied