Delivery receipts allow you to determine how many of your messages have been delivered successfully. They are passed back to your account by the carrier, and as a result there may be a small additional cost for each receipt.
In Account Settings, you will see that the default setting is to always request delivery receipts. By clicking on the switch, you can toggle this option on or off:
When would I turn off delivery receipts?
Without delivery receipts, you will have no ability to track the delivery rates or effectiveness of your campaign, so we do not recommend turning them off.