/// The MAPIFindNext function retrieves the next (or first) message identifier of a specified type

  public static extern uint MAPIFindNext(IntPtr lhSession, IntPtr ulUIParam, string lpszMessageType,

  /// If this flag is not set, MAPIFindNext can return any message of the specified type.

  /// MAPIFindNext calls can take longer if this flag is set.

  /// MAPIFindNext will succeed without this flag set as long as lpszMessageID is large enough

  /// MAPIFindNext will fail.