This topic describes how to identify messages in Simple Message Queue (formerly MNS).
You can use a message ID to identify each message in a queue or topic. The ID of a message is unique within a queue or topic, but is not unique among different queues or topics.
When a message is sent to an SMQ queue or topic, SMQ generates an ID for the message and the ID cannot be changed.
When a message is retrieved from the SMQ queue, the message body, message ID, and receipt handle are returned to the consumer. The consumer can then consume the message and delete the message within the invisibility period by using the receipt handle.