diff --git a/bureau/class/m_mail.php b/bureau/class/m_mail.php
index 70552b57..f4d76d35 100644
--- a/bureau/class/m_mail.php
+++ b/bureau/class/m_mail.php
@@ -75,6 +75,7 @@ class m_mail {
   var $srv_pop3;
   var $srv_pop3s;
 
+  var $cache_domain_mail_size = array();
   /* ----------------------------------------------------------------- */
   /** 
    * Constructeur
@@ -110,6 +111,19 @@ class m_mail {
      return $obj;
   }
 
+  function get_total_size_for_domain($domain) {
+    global $db;
+    if (empty($this->cache_domain_mail_size)) {
+      $db->query("SELECT SUBSTRING_INDEX(user,'@', -1) as domain, SUM(quota_dovecot) AS sum FROM dovecot_view group by domain ;");
+      while ($db->next_record() ) {
+        $dd = $db->f('domain');
+        $this->cache_domain_mail_size[ $dd ] = $db->f('sum');
+      }
+    }
+    if ( isset( $this->cache_domain_mail_size[$domain]) ) return $this->cache_domain_mail_size[$domain];
+    return 0;
+  }
+
   // FIXME documenter
   function catchall_getinfos($domain_id) {
     global $dom, $db;
diff --git a/bureau/class/m_quota.php b/bureau/class/m_quota.php
index f533503a..857a962d 100644
--- a/bureau/class/m_quota.php
+++ b/bureau/class/m_quota.php
@@ -459,7 +459,8 @@ class m_quota {
 
   /* sum of mailbox sizes for one domain */
   function get_size_mail_sum_domain($dom) {
-    return $this->_get_sum_sql("SELECT SUM(quota_dovecot) AS sum FROM dovecot_view WHERE user LIKE '%@{$dom}';"); 
+    global $mail;
+    return $mail->get_total_size_for_domain($dom);
   }
 
   /* count of mailbox sizes from all domains */