Write to abuse@abholer.link, in German or English, with the address concerned and roughly when the mail arrived.
An address is retired on request: it stops receiving, and what is in it goes at the 30-day mark. Addresses used to register accounts in another person's name, to receive fraudulent mail, or for anything illegal are retired and the pattern blocked.
Nothing here can send mail, so a message that claims to come from this domain did not come from here.