The Return Path Reputation Network Blacklist (RNBL) is compiled using a predictive model that analyzes hundreds of variables for each sending IP address. The blacklist scores IPs in real time based on volume data, spam traps, and complaint sources.
- Listings occur at the IP address level.
- The impact on deliverability is high.
- The RNBL is used by several mailbox providers based in the U.S.
If your IP gets listed, your deliverability will be affected at many mailbox providers. It will also affect your compliance status within the Return Path Certification program.
Reasons for getting listed
IP addresses are listed based on evidence of abusive behavior and sending mail that is inappropriate for a mail server. Examples include:
- Sending to spam traps
- Sending large amounts of mail resulting in complaints by end users
- Sending large volumes of mail to addresses that do not exist
- Sending large volumes of mail from IP addresses with no reverse DNS or IP addresses that appear to be dynamic
- Sending email from legitimate IP addresses that have not yet been allocated or delegated by the Internet Assigned Numbers Authority (IANA) or a delegated Regional Internet Registry (RIR)
How to get off this blacklist
IP addresses are automatically removed when the cause of the listing is resolved. You can request an immediate, temporary removal at the Return Path website while you investigate and correct the problem.
Return Path discloses the underlying reason for the listing upon request. If you don’t resolve the underlying problem, your IP address will likely be listed again.
Tips for staying off this list
- Use opt-in or confirmed opt-in permission methods for new subscribers
- Keep complaints low by only sending relevant and engaging email to users that ask to receive it
- Practice good list hygiene and suppression to avoid spam traps
- Ensure your IP address has a non-generic, unique reverse DNS (PTR) record
- Do not send email from a dynamic IP address