Mailjet users: Unsubscribe from list seems not to make it back to Mautic

Mautic 4.4.0

Your problem
My problem is :

  • Using Mailjet as ESP you loose unsubscribe information. Mails being sent via Mailjet will show the list unsubscribe in E-Mail clients - e.g. Apple Mail. Clicking unsubscribe from this list will be recorded by Mailjet - but this information doesn’t make it back to Mautic.

Steps I have tried to fix the problem :
Added the “Unsub” event also as webhook. Mautic responds with 200 OK. However, those unsubscribes will not be performed in Mautic. People may repeatedly try to unsubscribe this way - but still receive mail. This could become potentially pretty expensive, as this way to unsubscribe seems not to be implemented.

Is this the case? Unsubscribe only works through Mautic unsubscribe link, but not via unsubscribe header in the email client?