How do I enable MMS Delivery Receipts when sending messages?


Mara Wallace


MMS Delivery Receipts changes for API users

Beginning July 31, 2020, Bandwidth will support MMS Delivery Receipts (DLRs) when sending messages.

Bandwidth will automatically request DLRs when you send MMS or Group messages. As a result, you'll need to support all three possible callback events for Messaging: Message Delivered, Message Failed, and Message Sending

Most accounts are enabled by default for this functionality, but if you are not receiving the Message Sending callback, please reach out to your Bandwidth Support Team.


Callback messaging events

Bandwidth is introducing a new callback event for MMS. A message-sending callback event indicates the message is being sent to the downstream carrier and is waiting on the return of the requested DLR. This event will be sent before the message-delivered event on successful message authorization of MMS message. If the downstream provider doesn't return or support DLRs, you'll only receive this event to indicate the message was acknowledged by the downstream carrier but they provided no additional delivery information. 

The message-delivered event will now reflect a true message delivery for MMS and Group Messages, effectively representing an acknowledgment from the downstream provider that they've received the message. 

Note: Wireless carriers don't support handset DLRs on local numbers. When sending local messages, the delivery event you receive will represent delivery to the wireless carrier only. Where available from the carrier, toll-free and short code messages will reflect delivery to the handset.

When the carrier responds to the request for a DLR with a failed status and error code, you may receive a message-failed callback event. This callback will also include an error code that indicates why the message wasn’t deliverable. Please review the list of error codes or see our Troubleshooting section if you need help resolving the error. 

What if I don’t want to enable DLRs for MMS?

If you don’t request the MMS DLRs to be enabled on your account or request the functionality to be turned off, you’ll continue to receive a message-delivered event callback as you do today. This event will continue to indicate that  Bandwidth received the message, but it won’t reflect whether the downstream carrier confirmed the receipt of this message.

Note: If you don’t enable the MMS DLRs, you’ll continue to receive a callback without true delivery information.

For more information about the message delivered events, please see our developer docs. 

MMS HTTP messaging errors

Note: There will be new messaging delivery error codes specific to MMS. For the full list of error codes, please see our developer docs. 

Delivery error code

Error code description

Explanation of error



This error indicates the message is formatted incorrectly. 



There was an error retrieving the media from the media web server. Check the media URL and try to access it directly to see if the media can be fetched successfully.



The total size of MMS message media/attachments exceeded the max file size supported.



The message failed because the media content type isn't supported. 



The upstream provider doesn't exist in our configuration.



The destination is considered forbidden when the account isn't provisioned for that destination. 



The maximum limit of 10 participants in a Group has been exceeded. 

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