Check Types

RBL Checks

About RBL Checks

RBL, or DNSBL, stands for "Real-time Black List," and are most often used to publish the addresses of computers or networks linked to spamming, malware, or other abuses which system administrators may want to block from accessing their networks.

There are hundreds of RBLs in existence, which use a wide array of criteria for listing and delisting of addresses. These may include listing the addresses of zombie computers or other machines being used to send spam, listing the addresses of ISPs who willingly host spammers, or listing addresses which have sent spam to a honeypot system.

If the IP addresses of your servers appear on these RBLs, there's a good chance you'll have difficulty interacting with networks that subscribe to these RBLs. For instance, if your SMTP server is listed, you'll likely be unable to send email to anyone who's SMTP server uses the RBL you are listed on.

Each RBL provider determines which IP addresses are on their RBL and what hoops you must jump through to get delisted. NodePing does not provide delisting services. We only provide monitoring and alerts to let you know if your hostnames and IP addresses appear in the RBLs. Below is the list of RBLs we test along with links to help you get your IP addresses delisted.


When to use RBL Checks

RBL checks should be run for all servers that send email - including SMTP and web servers - on at least a daily basis. RBL check can test any ipv4 address or FQDN.

Using RBL Checks

To set up an RBL check,

  1. Select RBL from the Check type drop down.
  2. Give it a friendly label to identify this check in lists and notifications.
  3. Set how often you want the check to run on the Check Frequency field. Every 15 minutes to once a day is sufficient.
  4. Set the IP address or fully qualified domain name (FQDN) you want to test in the field marked Host Name or IP to check:.
  5. If you would like to ignore the results from certain RBLs, type the names of the RBLs separated by commas in the Ignore these RBL's: field.
  6. Set the Sensitivity. Very High is usually appropriate as rechecking yields the same results.
  7. Set the notifications you want for this check.
Common usage:
  • To ensure your email isn't rejected or automatically marked as spam, It is highly recommended you test your SMTP server by entering the name or IP address in the Host Name or IP to check: field.
  • RBL Check frequency of more often than 15 mins isn't recommended. Most RBL services only update their lists once an hour.

Other considerations

Currently only IPv4 addresses are supported