title: Can I send an email with an optional Email-field (Wordpress Contact-Form-7)?
body: <p>On my wordpress page there is a formular where a user can sign in for events. Now the user should decide if he/she would like to add an email adress. Only when an email is given the plugin should send an email.</p>
  
  <p>formular:</p>
  
  <pre><code>&lt;label&gt;Firstname:&lt;/label&gt;
  [text* firstname class:form-control]
  
  &lt;label&gt;Lastname:&lt;/label&gt;
  [text* lastname class:form-control]
  
  &lt;label&gt;Email:&lt;/label&gt;
  [text email class:form-control]
  
  [submit "Sign in"]
  </code></pre>
  
  <p>The problem now is that I cannot add the <code>[email]</code> attribute on the email tab. I get only a configuration error, because the field must not be empty. </p>
  
  <p>The only solution I can think of is to make the email field required and fill the field with a default value before sending using Javascript. Is there a better way to resolve this? </p>