Addition of RawDlrDoneDate to Delivered and Undelivered Status Webhooks

In order to provide additional information and transparancy around delivery timing we are adding a new parameter (RawDlrDoneDate) to Delivered and Undelivered status update webhooks for MMS and SMS messages. This parameter is a passthrough of the Done Date included on the DLR (Delivery Receipt) that we receive from our carrier partners. It takes the format of YYMMDDhhmm where:

YY = last two digits of the year (00-99)

MM = month (01-12)

DD = day (01-31)

hh = hour (00-23)

mm = minute (00-59)

Important notes on this data:

The format only includes minute level precision.

• The format does not provide timezone information. In practice, the timezone offset varies between carrier partners and even within the same carrier.
• Because of SMS/MMS signaling intricacies, not all messages will receive a RawDlrDoneDate in the Delivered or Undelivered status. Not all carrier partners offer DLRs and some messages go undelivered before a DLR is available.
• This parameter will also be added to Event Streams in the near future. Integrating with the parameter in event streams will require upgrading to a new schema version.
• The feature will be rolled out gradually. We expect the vast majority of Delivered/Undelivered messages to include the data by the end of February 2023.

It is strongly recommended that you use a Twilio provided signature validation library to verify the provenance of all webhooks arriving at your servers. The specific ordering and parameters included with each webhook depend on a number of factors and will evolve over time; thus it is important to follow the full specification of signature validation. This is already fully implemented and tested in the Twilio provided SDKs.