You end up on this Spamhaus list, because your server IP address is deemed a “client” or “end-user” IP, not a static server IP.
That would be a violation of the requirements, as with such IP addresses you cannot have your own reverse DNS entry (PTR record)
So if you are using your home internet connection, you cannot do anything about it. Otherwise contact your hoster and let him resolve that with Spamhaus, or have the hoster assign you a different IP address which is not listed on any blacklist.
