What does 'RBL Listed' mean?

Your IP address has been listed on a RBL (real-time block list).

This indicates that your server has probably been sending out a high volume of unsolicited email, your computer or server has been misconfigured or has been compromised

Why would this be bad?

Depending on the problem, your server can potentially be used by malicous users on the internet to send spam or do harm to others while using your server as a proxy.

If your server remains listed on this RBL you will have trouble sending email to lots of recipients.

Recommended action

In the case of a misconfiguration it could for example be the case that your SMTP server is accepting email from untrusted sources and you will need to reconfigure your SMTP server.

In the case of a compromise your server might have been hacked or infected by a trojan.

If you have been accidently listed and have resolved the issue, you can request a delisting using the URL included in the ticket report. Do not attempt to request a delisting at a RBL without knowning for sure you have resolved the issue. If you request a delisting without solving the problem you might end up permanently listed on that RBL!

Tips to resolve this matter

Run a virus and/or malware scanner on the system to look for infections

You also might want to check and resolve listings on other RBL's, using a RBL checker such as: http://www.anti-abuse.org/multi-rbl-check/

Getting more information

http://www.anti-abuse.org/multi-rbl-check