Added note about other MUAs (thanks RN)

i2p2www/pages/site/docs/applications/supported.html

@@ -310,6 +310,19 @@ email service by default.
 {%- endtrans %}
     <sup><em>[{{ _('bundled') }}]</em></sup></p>
   </li>
+
+  <li>
+    <p><strong>Sylpheed Claws, Thunderbird, other MUAs</strong> —
+{% trans reviews='http://'+i2pconv('hq.postman.i2p')+'/?page_id=9',
+smtp='http://'+i2pconv('hq.postman.i2p')+'/?page_id=10',
+pop3='http://'+i2pconv('hq.postman.i2p')+'/?page_id=11' -%}
+Can be configured to use Postman's email service. See
+<a href="{{ reviews}}">this comparison of MUAs</a>,
+and configuration settings for
+<a href="{{ smtp }}">SMTP</a> and <a href="{{ pop3 }}">POP3</a>.
+{%- endtrans %}
+    <sup><em>[{{ _('standalone') }}]</em></sup></p>
+  </li>
 </ul>
 
 <h3 id="file-sharing"><a href="#TOC">{% trans %}File Sharing{% endtrans %}</a></h3>