private void FaxMsg(object sender, NewMailEventArgs e)
 {
     Console.WriteLine("Sending mail to Post office:");
     Console.WriteLine($" From={e.From}, To={e.To}, Subject={e.Subject}");
 }
        public void SimulateNewMail(string from, string to, string subject)
        {
            NewMailEventArgs e = new NewMailEventArgs(from, to, subject);

            OnNewMail(e);
        }
 private void FaxMsg(object sender, NewMailEventArgs e)
 {
     Console.WriteLine("Faxing mail message:");
     Console.WriteLine($" From={e.From}, To={e.To}, Subject={e.Subject}");
 }
 protected virtual void OnNewMail(NewMailEventArgs e)
 {
     Volatile.Read(ref NewMail)?.Invoke(this, e);
 }