Managing Authorize.Net Email Receipts
If you're using Authorize.Net to process your online payments, your customers may be receiving a second email receipt with their order. The Open Dining system always sends your customers an email receipt, but Authorize.Net also is commonly configured to send its own confirmation email.
If you want to change your Authorize.Net email receipt settings, those are managed within the Authorize.Net back end system. Please see their support site for more information.