title: Why does MailAddress think 'john@gmail.' is a valid email address?
body: <p>Like a good C# user, I use the <a href="https://stackoverflow.com/questions/1903356/email-validation-regular-expression/1903368#1903368"><code>MailAddress</code></a> object to validate email addresses.</p>
  
  <p>A client of mine entered <code>john@gmail.</code> for his email, which was validated by <code>MailAddress</code>, and broke my software.  I'd expect the code below to throw an exception, but it doesn't.</p>
  
  <pre><code>static void Main(string[] args)
  {
      string addressmail = string.Empty;
  
      try
      {
          MailAddress mail = new MailAddress(@"john@gmail.");
          addressmail = mail.Address;
      }
      catch (FormatException)
      {
          // address is invalid
      }
  
      // address is valid
      Console.WriteLine(addressmail);
  }
  </code></pre>
  
  <p>Do you know how to catch this kind of bogus mail address?</p>