Skip to content

What is a Blacklist?

A blacklist is a list of IP addresses, domains, or email servers that have been flagged as sources of spam, malicious activity, or other harmful behavior. When an IP address appears on a blacklist, networks, mail servers, and security systems will use that information to block or filter traffic coming from it. 

Blacklists are maintained by a range of organizations, including cybersecurity companies, internet service providers, and independent tracking services. An IP address can end up on a blacklist for a number of reasons: sending bulk spam, hosting malware, being associated with bot activity, or showing signs of abuse. Sometimes legitimate users end up listed because they share an IP with bad actors, which is common with shared IP addresses on large hosting platforms. 

Getting removed from a blacklist typically requires identifying and resolving the underlying issue, then submitting a delisting request to the organization that manages the list. The process and timeline vary depending on which blacklist is involved.