By default, WHM gives you the option of using Spamhaus and/or Spamcop for added SPAM protection for incoming email. If you have additional DNSBL’s (DNS-based RBL’s) that you want Exim to check email against, you can easily enable them if you’re running cPanel 11.28 or higher.
First, go to WHM > Exim Configuration Editor, and click the RBLs tab.
Click Manage Custom RBLs, and you’ll see a list of any existing RBL’s that have already been enabled.
Under Add a new RBL, enter the information for the RBL you would like to add:
| RBL Name | the name of the RBL, used only for reference |
| RBL Info URL | the url that shows up in bounce messages for blocked email, telling the sender where a lookup can be done to verify or remove a listed IP |
| DNS list | The hostname of the DNSBL |
Examples:
![Screen Shot 2020 06 23 at 09.57.51 - WARNING: [pool user_USERNAME] server reached pm.max_children setting (25), consider raising it](https://i0.wp.com/administrator.pejcic.rs/wp-content/uploads/2026/09/Screen-Shot-2020-06-23-at-09.57.51.png?resize=344%2C194&ssl=1 "WARNING: [pool user_USERNAME] server reached pm.max_children setting (25), consider raising it")
![2023 08 28 12 15 - node[175421]: pthread_create: Resource temporarily unavailable](https://i0.wp.com/administrator.pejcic.rs/wp-content/uploads/2023/08/2023-08-28_12-15.png?resize=344%2C194&ssl=1 "node[175421]: pthread_create: Resource temporarily unavailable")