social/mail_tracking_mailgun/models/mail_tracking_event.py

# Copyright 2017 Tecnativa - David Vidal
# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).

from odoo import models, fields


class MailTrackingEvent(models.Model):
    _inherit = "mail.tracking.event"

    mailgun_id = fields.Char(
        string="Mailgun Event ID",
        copy="False",
        readonly=True,
    )

    def _process_data(self, tracking_email, metadata, event_type, state):
        res = super(MailTrackingEvent, self)._process_data(
            tracking_email, metadata, event_type, state)
        res.update({'mailgun_id': metadata.get('mailgun_id', False)})
        return res