diff --git a/addons/mail/mail_thread.py b/addons/mail/mail_thread.py
index 927e01e7406..41fcaf5adb7 100644
--- a/addons/mail/mail_thread.py
+++ b/addons/mail/mail_thread.py
@@ -1485,6 +1485,13 @@ class mail_thread(osv.AbstractModel):
         if context is None:
             context = {}
 
+        # TDE HACK: originally by MAT from portal/mail_mail.py but not working until the inheritance graph bug is not solved in trunk
+        # TDE FIXME: relocate in portal when it won't be necessary to reload the hr.employee model in an additional bridge module
+        if self.pool['res.groups']._all_columns.get('is_portal'):
+            user = self.pool.get('res.users').browse(cr, SUPERUSER_ID, uid, context=context)
+            if any(group.is_portal for group in user.groups_id):
+                return []
+
         threads = []
         if removed_suggested_threads is None:
             removed_suggested_threads = []
@@ -1498,4 +1505,4 @@ class mail_thread(osv.AbstractModel):
                 'image_small': thread.image_small
             }
             threads.append(data)
-        return sorted(threads, key=lambda x: (x['popularity'], x['id']), reverse=True)[:3]
\ No newline at end of file
+        return sorted(threads, key=lambda x: (x['popularity'], x['id']), reverse=True)[:3]
diff --git a/addons/portal/mail_mail.py b/addons/portal/mail_mail.py
index 84823bab747..e412732fdc9 100644
--- a/addons/portal/mail_mail.py
+++ b/addons/portal/mail_mail.py
@@ -44,14 +44,3 @@ class mail_mail(osv.Model):
             return _("""<small>Access your messages and documents through <a style='color:inherit' href="%s">our Customer Portal</a></small>""") % signup_url
         else:
             return super(mail_mail, self)._get_partner_access_link(cr, uid, mail, partner=partner, context=context)
-
-class mail_thread_portal(osv.AbstractModel):
-
-    _inherit = 'mail.thread'
-
-    def get_suggested_thread(self, cr, uid, removed_suggested_threads=None, context=None):
-        """Overwrite to avoid showing suggestions for anonymous users"""
-        anonymous_group = self.pool.get('ir.model.data').get_object(cr, SUPERUSER_ID, 'portal', 'group_anonymous')
-        if uid in [user.id for user in anonymous_group.users]:
-            return []
-        return super(mail_thread_portal, self).get_suggested_thread(cr, uid, removed_suggested_threads, context=context)