Adding Save() functionality to System.Net.Mail.MailMessage

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Mail;

namespace MailMessageExtension
{
    class Program
    {
        static void Main(string[] args)
        {
            MailMessage _testMail = new MailMessage();
            _testMail.Body = "This is a test email";
            _testMail.To.Add(new MailAddress("email@domain.com"));
            _testMail.From = new MailAddress("sender@domain.com");
            _testMail.Subject = "Test email";
            _testMail.Save(@"c:\testemail.eml");
        }
    }
}