Gmail provides a thread ID (X-GM-THRID) to associate groups of messages in the same manner as in the Gmail web interface. The thread ID is a 64-bit unsigned integer. This property is set only if server advertises XGMailExtensions1 extension support.

public string GmailThreadId { get; private set; }

Public Property GmailThreadId As String
	Get
	Private Set

public:
property String^ GmailThreadId {
	String^ get ();
	private: void set (String^ value);
}