Indicates the type of the callback: - message-received
for inbound callbacks. - One of message-sending
, message-delivered
, message-failed
for status callbacks.
-
MESSAGE_MINUS_RECEIVED
(value:'message-received'
) -
MESSAGE_MINUS_SENDING
(value:'message-sending'
) -
MESSAGE_MINUS_DELIVERED
(value:'message-delivered'
) -
MESSAGE_MINUS_FAILED
(value:'message-failed'
)