Mule ESB uses messages to pass data between different components of an application. A Mule message contains a core payload that holds the primary data to be processed, as well as ancillary attachments. The message also includes immutable inbound properties set by the message source and mutable outbound properties that can be added, removed, or modified by components in the flow.

1. Mule ESB

2. Mule Message Structure

3. The Mule Messages
Immutable data from the source of a
message
• Mutable data which will be carried out
of its current flow
• The core of the message
• Contains primary information to be
processed by Mule
• Contains a Java Object
• Ancillary information to the message
• Similar to an email attachment
• Inbound Properties: Mule Message
- Read-only Access
- Set from the Message Source
- Persists throughout the flow

4. Mule Inbound Properties

5. • Outbound Properties
- Read/Write Access
- Added by Property MP
- Ability to:
∙ Write
∙ Delete
∙ Copy

6. Mule Inbound Properties