A user identifier that can be used to authenticate the application when it attempts to connect to a messaging server. The user identifier is used in conjunction with the XMSC_PASSWORD property.
By default, the property is not set.
If you are connecting to WebSphere MQ, and you set the XMSC_USERID property of the connection factory, it must match the userid of the logged on user. If you do not set these properties, the queue manager will use the userid of the logged on user by default. If you require further connection-level authentication of individual users you can write a client authentication exit which is configured in WebSphere MQ. You can learn more about creating a client authentication exit in the Authentication topic in the WebSphere MQ Clients manual.