Defining a res.company on a partner should not set the company_name
on a mailing contact as the mailing contact is not linked to a
res.company.
The company_name should instead be set according to the commercial
partner of the partner being modified if it's parent_id is changed.
Before this patch, the module was designed after the [deprecated Mailgun webhooks][3]. However Mailgun had the [events API][2] which was quite different. Modern Mailgun has deprecated those webhooks and instead uses new ones that include the same payload as the events API, so you can reuse code.
However, this was incorrectly reusing the code inversely: trying to process the events API through the same code prepared for the deprecated webhooks.
Besides, both `failed` and `rejected` mailgun events were mapped to `error` state, but that was also wrong because [`mail_tracking` doesn't have an `error` state][1].
So the logic of the whole module is changed, adapting it to process the events API payload, both through controllers (prepared for the new webhooks) and manual updates that directly call the events API.
Also, `rejected` is now translated into `reject`, and `failed` is translated into `hard_bounce` or `soft_bounce` depending on the severity, as specified by [mailgun docs][2]. Also, `bounced` and `dropped` mailgun states are removed because they don't exist, and instead `failed` and `rejected` properly get their metadata.
Of course, to know the severity, now the method to obtain that info must change, it' can't be a simple dict anymore.
Added more parameters because for example modern Mailgun uses different keys for signing payload than for accessing the API. As there are so many parameters, configuration is now possible through `res.config.settings`. Go there to autoregister webhooks too.
Since the new webhooks are completely incompatible with the old supposedly-abstract webhooks controllers (that were never really that abstract), support for old webhooks is removed, and it will be removed in the future from `mail_tracking` directly. There is a migration script that attempts to unregister old webhooks and register new ones automatically.
[1]: f73de421e2/mail_tracking/models/mail_tracking_event.py (L31-L42)
[2]: https://documentation.mailgun.com/en/latest/api-events.html#event-types
[3]: https://documentation.mailgun.com/en/latest/api-webhooks-deprecated.html
Up until now, the `sent` event type was never processed, probably because it "made no sense", as an unsent email would never trigger an event.
However, it makes sense to process it because you may have a local relay that transmits mails over to the mail provider. In those circumstances, you should have 2 "sent" events (one from the relay and another one from the provider).
Also marked some useless parts of code for removal.
@Tecnativa TT32365