The NordSpam IP Address Blacklist (BL) is a DNS based Blackhole List (DNSBL) that lists IP addresses and domains believed to be associated with spam, unsolicited bulk email (UBE), or other abusive internet activities like phishing, online scams, and ransomware. Its stated focus is primarily on activity targeting Nordic and European countries. Mail server administrators can use this blacklist data to filter and block incoming mail.
According to NordSpam, their listing policy is based on tracking sources of spam and abuse. The exact criteria for getting on the blocklist are not disclosed to prevent spammers from finding ways around their filters. All additions to this blacklist are manually moderated to help prevent false positives.
Technically, the NordSpam IP Address Blacklist (BL) is an RFC5782 compliant DNSBL operating on the query zone bl.nordspam.com. It supports both IPv4 and IPv6 addresses. When a listed IP is queried, the blacklist returns a positive response of 127.0.0.2. Queries can be made for both A records (to confirm the listing) and TXT records (to get more information).
This blocklist is run by The NordSpam Project, a nonprofit organization. The project is privately funded and sponsored by a few companies. Their main goal is to track spammers and spam-related activities, with a particular focus on those affecting European and Nordic countries. The service is free of charge for both commercial and non-commercial use.
Getting removed from the NordSpam IP Address Blacklist (BL) is a strictly manual process. It is important to note that listings do not expire automatically. Before requesting removal, you must identify and resolve the issue that caused the listing. NordSpam states that delisting requests that do not include an explanation of how the spam problem was fixed will likely be ignored.
Once submitted, requests are typically investigated and processed within 1 to 48 hours. NordSpam may decline a removal request if they believe the corrective actions taken are not sufficient to prevent future abuse.
The impact of being on the NordSpam IP Address Blacklist (BL) is considered low. However, any listing on a blacklist or blocklist can cause email delivery failures. If an email server administrator uses this specific list to filter inbound mail, your emails to their users will be blocked. Given the project's focus, you are more likely to experience deliverability issues when sending to recipients in Nordic and other European countries. A listing is a clear sign of a reputation problem that should be addressed to ensure email deliverability.