AggregatedDeliveryReceipt

Contains aggregated information about a Message's delivery statuses across all participants of a Conversation.

At any moment during delivering message to a Participant the message can have zero or more of following delivery statuses:

• Message considered as sent to a participant, if the nearest upstream carrier accepted the message.
• Message considered as delivered to a participant, if Twilio has received confirmation of message delivery from the upstream carrier, and, where available, the destination handset.
• Message considered as undelivered to a participant, if Twilio has received a delivery receipt indicating that the message was not delivered. This can happen for many reasons including carrier content filtering and the availability of the destination handset.
• Message considered as read by a participant, if the message has been delivered and opened by the recipient in the conversation. The recipient must have enabled read receipts.
• Message considered as failed to be delivered to a participant if the message could not be sent. This can happen for various reasons including queue overflows, account suspensions and media errors (in the case of MMS for instance).