The tests consist in sending a mail related to a record to a customer and checking that the record can be viewed through the embedded link: - either in the backend if the user is connected and has the right to - or in the portal otherwise It also test that if the embedded link is tampered, the access is forbidden. Task-2797311 closes odoo/odoo#105405 Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>