Open your DealMachine mobile app or log in with your computer to Dealmachine.com
Click the menu button in the top left (mobile only).
Click Default Mailing Options
Select an option for the field "Sending Mode"
Click "Update Default Options Only" or "Update Default Options and All Deals".
Note: Choosing Update Default Options Only will not affect all your existing Deals. To save the changes for all existing deals, choose "Update Default Options and All Deals.