# Copyright 2018 Tecnativa - Ernesto Tejeda # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html). from odoo import _, api, models from odoo.exceptions import ValidationError class MassMailingContactListRel(models.Model): _inherit = "mail.mass_mailing.list_contact_rel" @api.constrains("contact_id", "list_id") def _check_contact_id_partner_id_list_id(self): for rel in self: if rel.contact_id.partner_id: contacts = rel.list_id.contact_ids - rel.contact_id if rel.contact_id.partner_id in contacts.mapped("partner_id"): raise ValidationError( _("A partner cannot be multiple " "times in the same list") )