private void Clone( ICW <Outlook.MAPIFolder> folder, Outlook.AppointmentItem source, string categories) { using (var item = source.CopyTo(folder.Ref, Outlook.OlAppointmentCopyOptions.olCreateAppointment).AsCW()) { item.Ref.Subject = _env.UserName; item.Ref.Categories = categories; item.Ref.Save(); } }