diff --git a/addons/portal/wizard/portal_wizard.py b/addons/portal/wizard/portal_wizard.py
index e88c68379ab..e3047cd5edb 100644
--- a/addons/portal/wizard/portal_wizard.py
+++ b/addons/portal/wizard/portal_wizard.py
@@ -212,6 +212,7 @@ class wizard_user(osv.osv_memory):
             'subject': _(WELCOME_EMAIL_SUBJECT) % data,
             'body_html': '<pre>%s</pre>' % (_(WELCOME_EMAIL_BODY) % data),
             'state': 'outgoing',
+            'type': 'email',
         }
         mail_id = mail_mail.create(cr, uid, mail_values, context=this_context)
         return mail_mail.send(cr, uid, [mail_id], context=this_context)
diff --git a/addons/portal_sale/portal_sale.py b/addons/portal_sale/portal_sale.py
index 3556fd5ca0e..d4d5b64cea3 100644
--- a/addons/portal_sale/portal_sale.py
+++ b/addons/portal_sale/portal_sale.py
@@ -68,6 +68,7 @@ class sale_order(osv.Model):
                 '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,
+                'type': 'email',
             }
             mail_obj = self.pool.get('mail.mail')
             mail_id = mail_obj.create(cr, uid, mail_values, context=context)
@@ -128,6 +129,7 @@ class account_invoice(osv.Model):
                 '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,
+                'type': 'email',
             }
             mail_obj = self.pool.get('mail.mail')
             mail_id = mail_obj.create(cr, uid, mail_values, context=context)