[REV] mail: revert "[FIX] mail: remove suggested recipient"

Revert this fix, as it was not working as expected, and even
prevent to create a partner.

Revert of following PR: https://github.com/odoo/odoo/pull/103596



closes odoo/odoo#104689

Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>