The following TransportTransactionMode levels are supported
ReceiveOnlyUnreliable
Transport transaction - receive only
Azure Storage Queues use a Peek-Lock model to overcome the lack of transactions. The message is not removed from the queue directly after it is received, but it is hidden for 30 seconds. This prevents other instances from picking it up. If the receiver fails to process the message within that timeframe or if it explicitly abandons the message, the message will become visible again and other instances will be able to pick it up. ReceiveOnly transport transaction mode provides an at-least-once delivery model.
Unreliable (transactions disabled)
The message is deleted from the queue directly after the receive operation completes and before it is processed.