If the option 'Reload from attachment' is checked for a report, it will be generated from the existing attachments. However, for snailmail, we have to force the re-rendering to apply specific css rules to match the layout of a A4 letter. Task-ID: 2008896 closes odoo/odoo#34053 Signed-off-by: Rémi Rahir (rar) <rar@odoo.com>