The Abusix Combined Blocklist is a real-time IP-based blacklist (or blocklist) used for filtering inbound email. It aggregates several of Abusix's recommended IP lists into a single, efficient query. This combined blacklist includes their black, exploit, and policy IP lists, making it a comprehensive tool for identifying and blocking malicious or unwanted mail sources. It operates on both IPv4 and IPv6 addresses.
Technically, mail servers query this blocklist using the DNS zone combined.mail.abusix.zone. A positive match results in a specific return code, which tells the mail server why the IP was listed. These codes help administrators understand the nature of the issue. The return codes for this blacklist are:
Abusix, the organization behind the blocklist, is a prominent company in network abuse management, email security, and threat intelligence. Their primary goal is to foster a safer internet by stopping threats before they can impact end-users. Abusix focuses on securing the primary channels for cyberattacks, like email and network traffic, by providing services to Internet Service Providers, telecommunication companies, and cloud providers.
Before requesting removal from this blacklist, it is crucial to identify and fix the root cause of the listing. Listings on the Abusix Combined Blocklist are not random; they occur due to specific activities detected from your IP address. The most common reasons include:
Once you have resolved the underlying issue, you can request to be delisted. Abusix requires you to create a free account to manage delistings. This policy is in place to prevent anonymous abuse of the removal process. To remove your IP, go to the Abusix Lookup and Delisting page. From there, you can enter your IP address, view the reason for the listing, and follow the on-screen instructions to sign up and request removal. Delisting is processed immediately, but due to DNS caching, it can take up to five minutes for the change to propagate fully.
The impact of being on the Abusix Combined Blocklist is considered medium. While not as universally adopted as some of the largest industry blocklists, it is used by a significant number of Internet Service Providers, hosting companies, and businesses to protect their mail servers. A listing on this blacklist will lead to email delivery failures and bounce messages from any recipient whose email provider uses this data. Resolving a listing should be a priority to restore email deliverability to affected domains.