Redirect MX Record For hMail Server

Sophos XG,

Hi All,

I am trying to set up hMail server in my home network, I created an A Mx Record an redirect to my wan ip. My hMail Server is in VM , I want to set up Mx record redirect from my sophos firewaal XG to my local VM ip. 

Please help me how i can set up.

Thank you :)