Spamhaus Project
IP and Domain
Reputation Checker
1

What is the purpose of the Hash Blocklist (HBL)

Back

What is the purpose of the HBL

What is the purpose of the HBL?

Identifying such elements in spam messages and then publishing them in HBL provides another means for administrators to filter their inbound email.

  • Mail server software is expected to be able to identify and extract these message elements, compute their cryptographic hashes, and compare them to HBL data.
  • Hash functions are a widely used industry standard that serve two purposes in HBL:
    • It reduces the size of the represented data to a unique, fixed-size string;
    • The hashes cannot be reverted to the original content. That precludes the disclosure of the content in distributed data which may be disallowed by specific privacy laws.
Back
Spamhaus Project

© 2022 Spamhaus. All Rights Reserved.

  • FAQs
  • Privacy Policy
  • Cookie Policy