Specifies the Id of the transaction that outgoing messages are associated with.
This property must either be empty, or set to the Id of a currently open transaction. The OpenTransactions configuration setting can be queried at any time to retrieve a comma-separated list of currently open transactions' Ids.
Note that this property only affects outgoing messages. It is also possible to send a message acknowledgment as part of a transaction by setting the AckTransactionId configuration setting during the MessageIn event handler.
Refer to BeginTransaction for more information about transactions.
This property is not available at design time.