title: Get Informed by E-mail after an database change or an event in PHP
body: <p>I have a PayPal button to pay for an item. Every time the button appears I generate in <code>PHP</code> a <code>UUID</code> and add it to the button with tag <code>"custom"</code>.</p>
  
  <pre><code>&lt;form action="https://www.paypal.com/cgi-bin/webscr" method="post" target="_top" class="payPalBtn"&gt;
  &lt;input type="hidden" name="custom" value="b1890a0d-c7c6"&gt;
  &lt;input type="hidden" name="cmd" value="_s-xclick"&gt;
  &lt;input type="hidden" name="hosted_button_id" value="WT1A5CCD4V1"&gt;
  &lt;input type="image" src="https://www.paypalobjects.com/he_IL/IL/i/btn/btn_paynowCC_LG.gif" border="0" name="submit" alt="PayPal"&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>After successful payment, PayPal redirect me to a page where this <code>UUID</code> number is sent back, so I know that for record X for example the payment is done. I update it in the server database and all fine. 
  The question is how can I be informed by email after I change the status of item X to PAID. I need to know this as fast as it changed.</p>