It looks like your domain currently has MX records set to use Google's mail service, so the emails for the domain are being directed to Google's servers. If you'd like to switch that over to our Email Hosting service, you would just need to remove those records and replace them with ours. There's a guide on how to do that here:
How can I use your Email Hosting for email only? https://www.dynadot.com/community/help/question/basic-hosting-for-email