Add A and AAAA records for rp.postal.example.com (#88)

Author: deanpcmad

content/2.getting-started/4.dns-configuration.md

@@ -110,6 +110,16 @@ The return path domain is the default domain that is used as the `MAIL FROM` for
     </tr>
   </thead>
   <tbody>
+    <tr>
+      <td>rp.postal.example.com</td>
+      <td>A</td>
+      <td><code>192.168.1.3</code></td>
+    </tr>
+    <tr>
+      <td>rp.postal.example.com</td>
+      <td>AAAA</td>
+      <td><code>2a00:1234:abcd:1::3</code></td>
+    </tr>
     <tr>
       <td>rp.postal.example.com</td>
       <td>MX</td>