RBL, short for Realtime Blackhole List, is a list of IP addresses whose owners refuse to stop the proliferation of spam. The RBL usually lists server IP addresses from ISPs whose customers are responsible for the spam and from ISPs whose servers are hijacked for spam relay.
If you choose to use RBL's on your server, please limit the number of lists you query. This will impact the performance of your mail server.
- Log into your Plesk Control Panel.
- Click on Tools & Settings, located in the left-menu.
- Click on Mail Server Settings.
- Un-check the box labelled Switch on spam protection based on DNS blackhole lists.
- Click OK to save.