An IP address of one of our servers was blacklisted due to the wrong activities of one of my customers. His WordPress site got hacked due to his use of the nulled plugin. After that, the hacker used our server to send hundreds of thousands of spam emails. As a result, our IP address was blacklisted by Spamhaus. Due to this incident, we removed the entire website at the customer’s request and temporarily removed the hosting account related to the domain name. After that, even though we have whitelisted the IP address several times, it is repeatedly blacklisted by Spamhus. What is the reason for this? Is there any other alternative solution for this? The other thing I want to know is whether there is a limited number of times we can whitelist in Spamhaus. ?