title: How to validate email in mongoose
body: <p>Im new to Mongoose...I have a code snippet below. If I want to check what comes after the @ symbol in an email before I save, how would I do that validation?</p>
  
  <pre><code>var user = new User ({
       firstName: String,
       lastName: String,
       email: String,
       regDate: [Date]
  });
  
  user.save(function (err) {
    if (err) return handleError(err);
  })
  </code></pre>