diff --git a/addons/account/account_invoice.py b/addons/account/account_invoice.py
index 3defd82d0ac..6cc3b367925 100644
--- a/addons/account/account_invoice.py
+++ b/addons/account/account_invoice.py
@@ -1779,12 +1779,13 @@ class res_partner(osv.osv):
         return super(res_partner, self).copy(cr, uid, id, default, context)
 
 
-class mail_compose_message(osv.osv):
+class mail_compose_message(osv.Model):
     _inherit = 'mail.compose.message'
 
     def send_mail(self, cr, uid, ids, context=None):
         context = context or {}
         if context.get('default_model') == 'account.invoice' and context.get('default_res_id') and context.get('mark_invoice_as_sent'):
+            context = dict(context, mail_post_autofollow=True)
             self.pool.get('account.invoice').write(cr, uid, [context['default_res_id']], {'sent': True}, context=context)
         return super(mail_compose_message, self).send_mail(cr, uid, ids, context=context)
 
diff --git a/addons/mail/wizard/mail_compose_message.py b/addons/mail/wizard/mail_compose_message.py
index 44396e5d143..0062b5e01bd 100644
--- a/addons/mail/wizard/mail_compose_message.py
+++ b/addons/mail/wizard/mail_compose_message.py
@@ -214,6 +214,9 @@ class mail_compose_message(osv.TransientModel):
                     new_attachments = email_dict.pop('attachments', [])
                     post_values['attachments'] += new_attachments
                     post_values.update(email_dict)
+                # automatically subscribe recipients if asked to
+                if context.get('mail_post_autofollow') and wizard.model and post_values.get('partner_ids'):
+                    active_model_pool.message_subscribe(cr, uid, [res_id], [item[1] for item in post_values.get('partner_ids')], context=context)
                 # post the message
                 active_model_pool.message_post(cr, uid, [res_id], type='comment', subtype='mt_comment', context=context, **post_values)
 
diff --git a/addons/purchase/purchase.py b/addons/purchase/purchase.py
index 95a952e243e..9aa3db887d2 100644
--- a/addons/purchase/purchase.py
+++ b/addons/purchase/purchase.py
@@ -1214,9 +1214,8 @@ class procurement_order(osv.osv):
             body = _("Draft Purchase Order created")
             self.message_post(cr, uid, [procurement.id], body=body, context=context)
 
-procurement_order()
 
-class mail_mail(osv.osv):
+class mail_mail(osv.Model):
     _name = 'mail.mail'
     _inherit = 'mail.mail'
 
@@ -1226,9 +1225,8 @@ class mail_mail(osv.osv):
             wf_service.trg_validate(uid, 'purchase.order', mail.res_id, 'send_rfq', cr)
         return super(mail_mail, self)._postprocess_sent_message(cr, uid, mail=mail, context=context)
 
-mail_mail()
 
-class product_template(osv.osv):
+class product_template(osv.Model):
     _name = 'product.template'
     _inherit = 'product.template'
     _columns = {
@@ -1238,13 +1236,14 @@ class product_template(osv.osv):
         'purchase_ok': 1,
     }
 
-product_template()
 
-class mail_compose_message(osv.osv):
+class mail_compose_message(osv.Model):
     _inherit = 'mail.compose.message'
+
     def send_mail(self, cr, uid, ids, context=None):
         context = context or {}
         if context.get('default_model') == 'purchase.order' and context.get('default_res_id'):
+            context = dict(context, mail_post_autofollow=True)
             wf_service = netsvc.LocalService("workflow")
             wf_service.trg_validate(uid, 'purchase.order', context['default_res_id'], 'send_rfq', cr)
         return super(mail_compose_message, self).send_mail(cr, uid, ids, context=context)
diff --git a/addons/sale/sale.py b/addons/sale/sale.py
index cf68ee01672..a37b6e2280a 100644
--- a/addons/sale/sale.py
+++ b/addons/sale/sale.py
@@ -1010,11 +1010,13 @@ class sale_order_line(osv.osv):
         return super(sale_order_line, self).unlink(cr, uid, ids, context=context)
 
 
-class mail_compose_message(osv.osv):
+class mail_compose_message(osv.Model):
     _inherit = 'mail.compose.message'
+
     def send_mail(self, cr, uid, ids, context=None):
         context = context or {}
         if context.get('default_model') == 'sale.order' and context.get('default_res_id') and context.get('mark_so_as_sent'):
+            context = dict(context, mail_post_autofollow=True)
             wf_service = netsvc.LocalService("workflow")
             wf_service.trg_validate(uid, 'sale.order', context['default_res_id'], 'quotation_sent', cr)
         return super(mail_compose_message, self).send_mail(cr, uid, ids, context=context)