SPF + DKIM pass and DMARC fails
<p>The domain s****g.nl has the following DMARC record:</p>

<blockquote>
  <p>"v=DMARC1; p=reject; rua=mailto:postmaster@s****g.nl,
  mailto:dmarc@s****g.nl"</p>
</blockquote>

<p>A valid SPF record for the sending mail server and none DKIM record.</p>

<p>The domain fo***de.com has a valid SPF and DKIM record.</p>

<hr>

<p><strong>Example 1</strong> </p>

<ul>
<li>From: from@s****g.nl</li>
<li>To: thetoadres@mail.com</li>
</ul>

<p>Result: </p>

<ul>
<li>SPF: PASS</li>
<li>DKIM: FAIL</li>
<li>DMARC: PASS</li>
</ul>

<hr>

<p><strong>Example 2</strong></p>

<ul>
<li>From: from@s****g.nl</li>
<li>Sender: response@fo***de.com</li>
<li>To: thetoadres@mail.com</li>
</ul>

<p>Result: </p>

<ul>
<li>SPF: PASS</li>
<li>DKIM: PASS</li>
<li>DMARC: FAIL</li>
</ul>

<hr>

<p>So when I send the email using a sender (on behalf of) the DMARC fails and the mail is <strong>not</strong> delivered.</p>

<p>Is there a explanation for this and maybe a solution to send emails on behalf of a domain which contains a DMARC reject policy and have a valid SPF for the sending mailserver?</p>

<p>Edit:  </p>

<p>[Screenshot results...][1]</p>