Zammad should support Bounce Address Tag Validation (BATV)

Zammad does not recognize BATV emails.

for more infos see the wikipedia site - Bounce Address Tag Validation - Wikipedia

As a result duplicate zammad contacts will be created.

The problems listed in the mentioned wikipedia entry sound like I wouldn’t want that bounce tag support.

I smell possible phishing attacks with the approach you’re requesting.
Up to now I also never seen these in the wild to be honest. Not sure how common they are.

Providers like Microsoft and Ionos (only as examples I have actual bounces from right now) don’t seem to use these as well.

This should be implemented on the mail server / mail relay server in my opinion