diff --git a/addons/account/models/account_invoice.py b/addons/account/models/account_invoice.py
index 48f7756c7e5..164f79bfa2a 100644
--- a/addons/account/models/account_invoice.py
+++ b/addons/account/models/account_invoice.py
@@ -41,7 +41,7 @@ MAGIC_COLUMNS = ('id', 'create_uid', 'create_date', 'write_uid', 'write_date')
 
 class AccountInvoice(models.Model):
     _name = "account.invoice"
-    _inherit = ['mail.thread', 'mail.activity.mixin', 'portal.mixin']
+    _inherit = ['portal.mixin', 'mail.thread', 'mail.activity.mixin']
     _description = "Invoice"
     _order = "date_invoice desc, number desc, id desc"
 
@@ -875,10 +875,11 @@ class AccountInvoice(models.Model):
     def _notification_recipients(self, message, groups):
         groups = super(AccountInvoice, self)._notification_recipients(message, groups)
 
-        for group_name, group_method, group_data in groups:
-            if group_name == 'customer':
-                continue
-            group_data['has_button_access'] = True
+        if self.state not in ('draft', 'cancel'):
+            for group_name, group_method, group_data in groups:
+                if group_name == 'customer':
+                    continue
+                group_data['has_button_access'] = True
 
         return groups
 
diff --git a/addons/mail/models/mail_thread.py b/addons/mail/models/mail_thread.py
index 32639ae75a9..955d9ac4479 100644
--- a/addons/mail/models/mail_thread.py
+++ b/addons/mail/models/mail_thread.py
@@ -634,7 +634,7 @@ class MailThread(models.AbstractModel):
         local_kwargs.pop('res_id', None)
 
         if link_type in ['view', 'assign', 'follow', 'unfollow']:
-            params = dict(base_params)
+            params = dict(base_params, **local_kwargs)
             base_link = '/mail/%s' % link_type
         elif link_type == 'controller':
             controller = local_kwargs.pop('controller')
diff --git a/addons/portal/models/portal_mixin.py b/addons/portal/models/portal_mixin.py
index 62dc8403956..ec11771c571 100644
--- a/addons/portal/models/portal_mixin.py
+++ b/addons/portal/models/portal_mixin.py
@@ -3,7 +3,7 @@
 
 from werkzeug.urls import url_encode
 
-from odoo import api, fields, models
+from odoo import api, fields, models, _
 
 
 class PortalMixin(models.AbstractModel):
@@ -18,6 +18,27 @@ class PortalMixin(models.AbstractModel):
         for record in self:
             record.portal_url = '#'
 
+    def _get_access_token_field(self):
+        """ Give the field used to fetch the customer portal access token, if
+        any. Override this method if the field holding the token is named
+        differently. """
+        return 'access_token' if 'access_token' in self else False
+
+    def _get_customer_field(self):
+        """ Give the field used to fetch the customer partner_id, if any.
+        Override this method if the field holding the token is named differently. """
+        return 'partner_id' if 'partner_id' in self else False
+
+    def _get_access_token(self):
+        """ Get the current record access token """
+        field = self._get_access_token_field()
+        return self[field] if field else False
+
+    def _get_customer(self):
+        """ Get the current record custome (res.partner record) """
+        field = self._get_customer_field()
+        return self[field] if field else self.env['res.partner']
+
     def get_share_url(self):
         self.ensure_one()
         params = {
@@ -30,3 +51,28 @@ class PortalMixin(models.AbstractModel):
             params.update(self.partner_id.signup_get_auth_param()[self.partner_id.id])
 
         return '/mail/view?' + url_encode(params)
+
+    @api.multi
+    def _notification_recipients(self, message, groups):
+        access_token = self._get_access_token()
+        customer = self._get_customer()
+
+        if access_token and customer:
+            additional_params = {
+                'access_token': self.access_token,
+            }
+            additional_params.update(customer.signup_get_auth_param()[customer.id])
+            access_link = self._notification_link_helper('view', **additional_params)
+
+            new_group = [
+                ('portal_customer', lambda partner: partner.id == customer.id, {
+                    'has_button_access': False,
+                    'button_access': {
+                        'url': access_link,
+                        'title': ('View %s') % self.env['ir.model']._get(message.model).display_name,
+                    },
+                })
+            ]
+        else:
+            new_group = []
+        return super(PortalMixin, self)._notification_recipients(message, new_group + groups)
diff --git a/addons/project/models/project.py b/addons/project/models/project.py
index 4b824ded373..319f50724b6 100644
--- a/addons/project/models/project.py
+++ b/addons/project/models/project.py
@@ -68,7 +68,7 @@ class ProjectTaskType(models.Model):
 class Project(models.Model):
     _name = "project.project"
     _description = "Project"
-    _inherit = ['mail.alias.mixin', 'mail.thread', 'portal.mixin']
+    _inherit = ['portal.mixin', 'mail.alias.mixin', 'mail.thread']
     _inherits = {'account.analytic.account': "analytic_account_id"}
     _order = "sequence, name, id"
     _period_number = 5
@@ -444,7 +444,7 @@ class Task(models.Model):
     _name = "project.task"
     _description = "Task"
     _date_name = "date_start"
-    _inherit = ['mail.thread', 'mail.activity.mixin', 'portal.mixin', 'rating.mixin']
+    _inherit = ['portal.mixin', 'mail.thread', 'mail.activity.mixin', 'rating.mixin']
     _mail_post_access = 'read'
     _order = "priority desc, sequence, date_start, name, id"
 
diff --git a/addons/sale/models/sale.py b/addons/sale/models/sale.py
index a646f5e0ed3..271bea23781 100644
--- a/addons/sale/models/sale.py
+++ b/addons/sale/models/sale.py
@@ -19,7 +19,7 @@ from odoo.addons import decimal_precision as dp
 
 class SaleOrder(models.Model):
     _name = "sale.order"
-    _inherit = ['mail.thread', 'mail.activity.mixin', 'portal.mixin']
+    _inherit = ['portal.mixin', 'mail.thread', 'mail.activity.mixin']
     _description = "Quotation"
     _order = 'date_order desc, id desc'