title: Bootstrap email validation
body: <p>I'm using Bootstrap to validate email address: </p>
  
  <pre><code>&lt;form id="..." novalidate&gt;
  ...
  &lt;div class="form-group"&gt;
      &lt;input type="email" class="form-control" id="..." required/&gt;
          &lt;div class="invalid-feedback"&gt;
              Please provide a valid email.
          &lt;/div&gt;
  &lt;/div&gt;
  ...
  &lt;/form&gt;
  </code></pre>
  
  <p>I'm using <i>novalidate</i> property to allow Bootstrap validate email itself. 
  My HTML contains both Bootstrap CSS and JS refs. Everything works fine.</p>
  
  <p>But I have couple of questions:</p>
  
  <ol>
  <li>How bootstrap validates email regex? Where can I find code responsible for this (I've tried to look at srcs...)?</li>
  <li>Can I override regex that is used for validation (would be nice to do this without Bootstrap original code modification)? </li>
  </ol>
  
  <p>Thanks in advance. </p>