High priority, a Message with this priority will be processed before the ones with the default priority.
Use this for low priority messages, a Message with the default priority will be processed first.
The default priotity, this is the priority assigned to the Message by default.
The highest priority, use this for very urgent Message as they will be the first ones to be attended.
The lowest priority, the messages with this priority will be the last ones to be attended.
Priorities that can be set on a Message to instruct the message queue to process it before any other message with lower priority.