Because spammers can’t easily obtain new IP addresses through legitimate means, they frequently resort to stealing IP address blocks that are dormant and aren’t being utilized by the rightful owners. There is a thriving black market in IP addresses; spammers don’t care whether the source of their IP addresses is legitimate or even legal. A cybercriminal that can steal a large IP address block (for example, a /16 or 65,536 IP addresses) can generate thousands of dollars per month.
Here are 4 things that we recommend in order to stay off the UCEPROTECT-Blacklists and the Backscatterer List:
1. Do not use abusive techniques on your systems, and also tell your customers with their own servers not to do so.
The following techniques are considered abusive, even though some seem to have become very popular.
Sender callouts (also known as Sender Verify or SAV) or any other kind of Backscatter.
2. Ensure that large amounts of garbage cannot be sent through your mailservers / smarthosts.
3. Ensure that your dynamic / dialups / homeusers cannot be abused as spam zombies.
4. Get clue about new customers, secure your servers and prevent open relays and open proxies at your dedicated line customers and at customers with static IP addresses.