The MessageID header field contains a value that uniquely identifies each message sent by the QAnywhere client.
When a message is sent using QAManagerBase::putMessage method, the MessageID header is null and can be ignored. When the send
method returns, it contains an assigned value.
A MessageID is a qa_string value that should function as a unique key for identifying messages in a historical repository.
For more information about getting and setting message headers and properties, see QAnywhere messages.