title: Codeigniter 3 force valid email format
body: <p>I am building a CRUD application in Codeigniter 3. I have an "Add customer" form with an <em>email address</em> field among others. I have managed to make this field required like so:</p>
  
  <pre><code>$this-&gt;form_validation-&gt;set_rules('email', 'Email', 'required');
  </code></pre>
  
  <p>I also need to force a valid e-mail format. What nut I add to the code above?
  Thank you!</p>