diff --git a/docs/configure b/docs/configure
index 121d0b9..4fc2856 100644
--- a/docs/configure
+++ b/docs/configure
@@ -833,6 +833,19 @@ virtual_domain_alias:
 		and domainalias.domain_id = domains.domain_id}}
   retry_use_local_part
 
+# Fallback in case a postmaster account does not exist. Send mail to admin
+# accounts of the domain
+virtual_postmaster_fallback:
+  driver = redirect
+  allow_fail
+  data = ${lookup mysql{select username from users,domains where admin=1 \
+  		and domain = '${quote_mysql:$domain}' \
+		and users.domain_id = domains.domain_id}}
+  retry_use_local_part
+  file_transport = virtual_delivery
+  reply_transport = address_reply
+  pipe_transport = address_pipe_catchall
+
 
 # This router handles aliasing using a linearly searched alias file with the
 # name /etc/aliases. When this configuration is installed automatically,
diff --git a/vexim/adminuser.php b/vexim/adminuser.php
index bc123d9..2bfb7b5 100644
--- a/vexim/adminuser.php
+++ b/vexim/adminuser.php
@@ -90,14 +90,18 @@
         $sth->execute($queryParams);
         while ($row = $sth->fetch()) {
           if($row['enabled'] === 0) print '<tr class="disabled">'; else print '<tr>';
-          print '<td class="trash"><a href="adminuserdelete.php?user_id='
-            . $row['user_id']
-            . '&amp;localpart='
-            . $row['localpart']
-            . '">';
-          print '<img class="trash" title="Delete '
-            . $row['realname']
-            . '" src="images/trashcan.gif" alt="trashcan"></a></td>';
+	  print '<td class="trash">';
+	  if($row['localpart']!=='postmaster') {
+            print '<a href="adminuserdelete.php?user_id='
+              . $row['user_id']
+              . '&amp;localpart='
+              . $row['localpart']
+              . '">';
+            print '<img class="trash" title="Delete '
+              . $row['realname']
+              . '" src="images/trashcan.gif" alt="trashcan"></a>';
+          }
+	  print '</td>';
           print '<td><a href="adminuserchange.php?user_id=' . $row['user_id']
             . '&amp;localpart=' . $row['localpart']
             . '" title="' . _('Click to modify')
diff --git a/vexim/adminuserdelete.php b/vexim/adminuserdelete.php
index 3beb2e0..f9d54cd 100644
--- a/vexim/adminuserdelete.php
+++ b/vexim/adminuserdelete.php
@@ -4,12 +4,18 @@
   include_once dirname(__FILE__) . '/config/functions.php';
   include_once dirname(__FILE__) . '/config/httpheaders.php';
 
+# Do not allow to delete the postmaster (RFC5321)
+if ($_GET['localpart']==='postmaster') {
+  header ("Location: adminuser.php?faildeleted={$_GET['localpart']}");
+  die();
+}  
+  
 # confirm that the postmaster is looking to delete a user they are permitted to change before going further
 $query = "SELECT * FROM users WHERE user_id=:user_id
-	AND domain_id=:domain_id
+	AND domain_id=:domain_id AND localpart=:localpart
 	AND (type='local' OR type='piped')";
 $sth = $dbh->prepare($query);
-$sth->execute(array(':user_id'=>$_GET['user_id'], ':domain_id'=>$_SESSION['domain_id']));
+$sth->execute(array(':user_id'=>$_GET['user_id'], ':domain_id'=>$_SESSION['domain_id'], ':localpart'=>$_GET['localpart']));
 if (!$sth->rowCount()) {
   header ("Location: adminuser.php?faildeleted={$_GET['localpart']}");
   die();