MX records are mail exchange records that specify the mail server responsible for accepting email messages for your domain.
To set up your MX records using our DNS, please follow the instructions below:
Sign in to your Dynadot account.
Check the box next to your domain name(s) and click on the "Action" button.
Choose "DNS Settings" from the "Action" list.
On the DNS Settings page, select "Dynadot DNS" from the drop-down menu.
Under the "Domain Record (optional)" section, select "MX" from the "Record Type" drop-down.
Enter your MX record in the "IP Address or Target Host" box, and the record's priority in the "Distance" box.
Press the "Save Settings" button to save your changes.
To learn more checkout: https://www.dynadot.com/community/help/question/MX-DNS-set-up#:~:text=Check%20the%20box%20next%20to,Record%20Type%22%20drop%2Ddown.