DNSBL (Blacklist) Monitoring
DNSBL (DNS-based Blackhole Lists) are used to block spam. If your IP or domain ends up on a blacklist, your emails might not be delivered. Our DNSBL monitoring alerts you if this happens.
What Is DNSBL?
DNSBL stands for DNS-based Blackhole List. These are lists of IP addresses and domains that have been reported for sending spam or malicious content.
Email servers check these lists and may:
- Reject emails from listed addresses
- Mark emails as spam
- Delay delivery
Why Monitor Blacklists?
| Problem | Impact |
|---|---|
| Emails not delivered | Important messages never arrive |
| Marked as spam | Customers miss your emails |
| Reputation damage | Hard to recover once blacklisted |
| Unknown listing | You might not know you’re listed |
Regular monitoring catches listings early so you can take action.
Setting Up DNSBL Monitoring
- Go to Tools in the left menu
- Click DNSBL Monitors
- Click Add Entry
- Enter your IP address or domain
- Click Save
We’ll check major blacklists and alert you if listed.
What We Check
We monitor popular blacklists including:
- Spamhaus
- Barracuda
- SORBS
- SpamCop
- And many others
Each check queries multiple lists simultaneously.
Understanding Results
| Status | Meaning |
|---|---|
| Clear | Not listed on any blacklists |
| Listed | Found on one or more blacklists |
| Warning | Minor listing or reputation concern |
If You’re Blacklisted
Don’t panic. Here’s what to do:
1. Identify the Cause
- Was your server compromised?
- Did someone send spam through your mail server?
- Is there a misconfiguration?
2. Fix the Issue
- Secure your server
- Stop any spam from being sent
- Update passwords and security
3. Request Removal
Most blacklists have a removal process:
- Visit the blacklist’s website
- Look for a delisting request form
- Provide information about the fix
- Wait for review and removal
Preventing Blacklisting
| Best Practice | Why It Helps |
|---|---|
| Use strong passwords | Prevents account compromise |
| Enable SPF/DKIM/DMARC | Proves email authenticity |
| Monitor email sending | Catch unusual activity |
| Keep software updated | Prevents vulnerabilities |
See our email authentication guide for more.
Monitoring Multiple IPs
If you have multiple servers or IP addresses:
- Add each IP separately
- Add your domain as well
- Monitor all mail servers
This ensures complete coverage.