 <p>Ok, i found a way to do that. </p> <p>Basically i changed <code>trigger()</code> function to <code>debugEmail()</code>, and inside the <code>class-wc-email-customer-invoice.php</code> file, copied the <code>trigger()</code> into <code>debugEmail()</code> and removed the this line to avoid the send of the email: </p> <pre><code>$this-&gt;send( $this-&gt;get_recipient(), $this-&gt;get_subject(), $this-&gt;get_content(), $this-&gt;get_headers(), $this-&gt;get_attachments() ); </code></pre>