Overview
Hostkarma was a multi-category IP reputation system that went beyond simple binary blacklisting. It maintained several lists: Black (confirmed bad senders), White (verified good senders), Brown (uncertain reputation), Yellow (bulk mailers), and Nobl (no data). This nuanced approach allowed mail administrators to make more sophisticated filtering decisions.
Hostkarma Black specifically listed IPs with confirmed negative sending histories. The entire Hostkarma system has been discontinued and none of its lists are currently maintained.
How It Works
Hostkarma built its reputation data from email traffic analysis and community reports. The Black list required consistent evidence of abusive sending β a single incident would more likely result in a Brown listing. The system tracked sending history over time, allowing IPs to graduate between categories based on behavior changes.
How to Get Delisted
The Hostkarma system is no longer active. No removal requests can be submitted. If a mail filter still references Hostkarma Black, the configuration is outdated and should be updated to use active reputation services. Historically, improving sending behavior would allow an IP to migrate from Black to Brown to White over time.