public static bool IsMessage(string itemClass, bool includeCalendaringMessages = false) { bool flag = ObjectClass.IsOfClass(itemClass, "IPM.Note") || ObjectClass.IsOfClass(itemClass, "REPORT"); if (includeCalendaringMessages) { flag |= (ObjectClass.IsMeetingMessage(itemClass) || ObjectClass.IsMeetingMessageSeries(itemClass)); } return(flag); }