Allows you un-assign a callback URL from a specific long code or toll-free phone number in your account to stop receiving notifications of inbound SMS or MMS messages, or delivery receipts (DLRs) of messages you have sent from that number.
The phone number to have its callback association removed.
Callback type to be removed. Allowed values are:
Called for inbound SMS messages (see Receive an SMS).
Called for inbound MMS messages (see Receive an MMS).
Called for SMS Delivery Receipts (see Receive a DLR).
Called for inbound MMS Delivery Receipts (see Receive a DLR).