title: How to create custom email headers
body: <p>I'm trying to create a custom email header to use the SendGrid api.  </p>
  
  <p>Here's what I'm doing - but its not working:</p>
  
  <pre><code>class Mailman &lt; ActionMailer::Base
    default :from =&gt; "info@sample.com"
  
    def send_message(name, email, message)
      @name = name
      @email = email
      @message = message
  
      mail(:to =&gt; 'info@sample.com',
       :from =&gt; email,
       :subject =&gt; "Message from the site",
       :headers['X-SMTPAPI'] =&gt; "category: Drip Email"
      )
    end
  
  end
  </code></pre>
  
  <p>Any help appreciated.</p>
  
  <p>Thanks,
  Adam</p>