diff --git a/functions/imap_general.php b/functions/imap_general.php
index 8bd2485ae..066fb4c2d 100755
--- a/functions/imap_general.php
+++ b/functions/imap_general.php
@@ -20,9 +20,12 @@
     */
     function sqimap_session_id() {
 
+        global $data_dir, $username;
+
         $IMAPSessionID = substr(session_id(), -4);
         if( $IMAPSessionID == '' ) {
-            $IMAPSessionID = GenerateRandomString(4, '', 7);
+            $IMAPSessionID = str_pad( dechex( getPref( $data_dir, $username, 'counter', 0 ) ),
+                                      4, '0', STR_PAD_LEFT);
         }
 
         return( $IMAPSessionID );
diff --git a/functions/prefs.php b/functions/prefs.php
index 5ecf530f9..1d5fb68fb 100644
--- a/functions/prefs.php
+++ b/functions/prefs.php
@@ -70,7 +70,7 @@
       if (isset($prefs_cache[$string]))
           return $prefs_cache[$string];
       else
-        return $default;
+          return $default;
    }
 
 
diff --git a/src/redirect.php b/src/redirect.php
index f40910576..011b14b28 100644
--- a/src/redirect.php
+++ b/src/redirect.php
@@ -104,6 +104,8 @@
         session_register ('username');
         setcookie('key', $key, 0, $base_uri);
         do_hook ('login_verified');
+        setPref( $data_dir, $username, 'counter',
+            getPref( $data_dir, $username, 'counter', 0 ) + 1 );
     }
 
     /* Set the login variables. */