How to set X-Mailgun-Campaign-Id header in Mailgun php API?
<p>How to set up header "X-Mailgun-Campaign-Id" in Mailgun php API?</p>

<p>I'm using the following code, but I don't know how to pass campaign ID in the header:</p>

<pre><code>Mail::send('email.message', $data, function ($message) use ($data) {
    $message-&gt;to($data['to_email'], $data['to_name'])
        -&gt;subject($data['subject'])
        -&gt;from($data['from_email'], $data['from_name'])
        -&gt;header('X-Mailgun-Campaign-Id', 'test campaign');
});
</code></pre>