odoo/addons/mail/security/ir.model.access.csv

1	id	name	model_id:id	group_id:id	perm_read	perm_write	perm_create	perm_unlink
2	access_mail_message	mail.message	model_mail_message		1	0	0	0
3	access_mail_thread	mail.thread	model_mail_thread		1	0	0	0