Sometimes, I don't understand Odoo and why a simple thing it's so complicated...
I understand that it's interesting that whatever sales user, could change opt_out option about marketing preferences, to indicate if a customer want or not receive emails, but the only way that I've found to enable this options to sales users is to enable configuration permission and then enable developer mode. (so this sales user, could change users, permission, etc...)
I supose that it should be a better way to do this, but I didn't found it. I need that sales users, could change opt_out checkbox in customer sales in Odoo 10
Thanks