SwissUli Welcome to the community!
Unfortunately, we cannot delist external IPs as we are not the owner of the IPs. Please click on this link. Once the page is open, click on More Info. There you have the possibility to request a delisting by filling out the form.
I also recommend that you contact your hosting provider and ask them how the listing in Spamhouse came about. They can certainly help you and check your online site for security flaws.
Greetings
Daniele
