diff --git a/addons/portal_sale/__init__.py b/addons/portal_sale/__init__.py
index 26c654db9dd..f61ac2a38dd 100644
--- a/addons/portal_sale/__init__.py
+++ b/addons/portal_sale/__init__.py
@@ -19,3 +19,4 @@
 #
 ##############################################################################
 
+import account_invoice
\ No newline at end of file
diff --git a/addons/portal_sale/account_invoice.py b/addons/portal_sale/account_invoice.py
new file mode 100644
index 00000000000..2f3a5e0a35c
--- /dev/null
+++ b/addons/portal_sale/account_invoice.py
@@ -0,0 +1,71 @@
+# -*- coding: utf-8 -*-
+##############################################################################
+#
+#    OpenERP, Open Source Management Solution
+#    Copyright (C) 2004-2011 OpenERP S.A (<http://www.openerp.com>).
+#
+#    This program is free software: you can redistribute it and/or modify
+#    it under the terms of the GNU Affero General Public License as
+#    published by the Free Software Foundation, either version 3 of the
+#    License, or (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU Affero General Public License for more details.
+#
+#    You should have received a copy of the GNU Affero General Public License
+#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+##############################################################################
+
+from osv import fields,osv
+
+class mail_mail(osv.osv):
+    _inherit = 'mail.mail'
+
+    def _postprocess_sent_message(self, cr, uid, mail, context=None):
+        if mail.model == 'account.invoice':
+            so_obj = self.pool.get('sale.order')
+            inv_obj = self.pool.get('account.invoice')
+
+            inv_follower_ids = inv_obj.read(cr, uid, mail.res_id, ['message_follower_ids'], context=context)['message_follower_ids']
+
+            cr.execute('SELECT rel.order_id FROM sale_order_invoice_rel AS rel WHERE rel.invoice_id='+str(mail.res_id))
+            so_invoice_ids = cr.fetchall()        
+            so_follower_ids = []
+            for so_invoice_id in so_invoice_ids:
+                order_id, = so_invoice_id
+                so_follower_ids += so_obj.read(cr, uid, order_id, ['message_follower_ids'], context=context)['message_follower_ids']
+
+            partner_ids = list(set(so_follower_ids).difference(set(inv_follower_ids)))
+
+            if partner_ids:
+                partner_obj = self.pool.get('res.partner')
+                user_obj = self.pool.get('res.users')
+                group_obj = self.pool.get('res.groups')
+
+                document = inv_obj.browse(cr, uid, mail.res_id, context=context)
+
+                # partners = partner_obj.read(cr, uid, partner_ids, ['user_ids'], context=context)
+                # for partner in partners:
+                #     users = user_obj.read(cr, uid, partner['user_ids'], ['groups_id'], context=context)
+                #     for user in users:                    
+                #         for group in group_obj.browse(cr, uid, user['groups_id'], context=context):
+                #             if group.is_portal == True:
+                #                 print 'Hello'
+                                # inv_obj.message_subscribe(cr, uid, [mail.res_id], partner_ids, context=context)
+                                # mail_values = {
+                                #     'email_from': 'vta@openerp.com',
+                                #     'email_to': 'falcobolger@gmail.com',
+                                #     'subject': 'Invitation to follow %s' % document.name_get()[0][1],
+                                #     'body_html': 'You have been invited to follow %s' % document.name_get()[0][1],
+                                #     'auto_delete': True,
+                                # }
+                                # mail_id = self.create(cr, uid, mail_values, context=context)
+                                # print mail_values
+                                # self.send(cr, uid, [mail_id], recipient_ids=[partner['id']], context=context)
+                                
+        return super(mail_mail, self)._postprocess_sent_message(cr, uid, mail=mail, context=context)
+
+mail_mail()
\ No newline at end of file