How can I change the bounce_notice_recipient email address?

Now it sends the non existet/deleted users’s emails to x@company.x but I would like to change it to y@company.x.

Create y@company.x and x@company.x as alias of y@company.x

Ok, but the x@company.x is a valid working email.
Postfix sends the mails here.

That’s was not written into the first post… Maybe a rule can help but maybe that’s not what you’re looking for.

Yes, a filter at the x@company.x email is okay. But this is not the correct solution.