Create a Triggered Send Using the Async API
By using the async API, you can ensure that your call is queued and ready to execute after the call is completed, even if your network connection is interrupted. You can also prioritize triggered sends and use the CorrellationID and ConversationID objects to track an exchange of emails related to the triggered send.
This feature isn't enabled by default in most accounts. For more information about enabling this feature, contact your Account Executive.