Ever heard of the Policy Blocklist (PBL)? 
It's a Spamhaus list you might actually want to be on! It helps tackle end-user abuse by listing IP ranges from which email should never be sent directly to the final destination.
Whether you're an Internet Service Provider with IP ranges to declare or an end user that has received a rejection error message mentioning "Spamhaus," understanding the PBL is essential.
Learn more about the PBL, how it works for providers, and its impact on end users here 
