RBLS - Email Blocklist & Reputation Tools
rbls.org checks IP addresses against real-time blocklists (RBLs/DNSBLs) to protect email deliverability. Monitor your mail server reputation, diagnose blacklist issues, and learn how to get delisted.
Available Tools
IP Reputation Check
Full IP reputation scan against 100+ blocklists (Spamhaus, Barracuda, SORBS, SpamCop, UCEProtect), threat intelligence feeds (IPsum, FireHOL), and abuse databases. Get instant listing status, reasons, and reputation scores.
Why Am I Blacklisted?
Understand common causes of blocklist listings: spam complaints, compromised servers, open relays, and shared hosting issues. Diagnose the root cause before attempting removal.
How Delisting Works
Step-by-step guide to removing your IP from major blocklists. Learn each RBL's specific removal process, timing expectations, and best practices for successful delisting.
Domain Reputation
Check any domain against URIBLs, threat databases (HaGeZi, Blackbook), and popularity rankings (Majestic, Tranco, Cloudflare Radar). Identify domains flagged for spam, phishing, or malware.
Why Check Blocklists?
Email deliverability depends on reputation. Major email providers (Gmail, Microsoft 365, Yahoo) check blocklists before accepting mail. Even one listing can cause your messages to be rejected or filtered to spam.
Early detection prevents damage. By the time users complain about bounced emails, you may have been listed for days. Regular monitoring catches problems before they escalate.
Different lists matter differently. A Spamhaus listing is critical. An obscure regional list may not matter. Understanding which lists affect your recipients helps prioritize remediation.
Common Use Cases
Email Administrators
- Check sending IPs before major campaigns
- Monitor mail server reputation continuously
- Verify IP reputation after security incidents
- Screen new IP addresses before deployment
Security Teams
- Investigate suspicious IPs appearing in logs
- Check if compromised hosts are already listed
- Assess damage after malware infections
Marketing Teams
- Verify email infrastructure before launches
- Diagnose sudden deliverability drops
- Confirm delisting after remediation
Understanding Results
Clean - IP not found on major blocklists. Good standing, but monitor regularly.
Listed (Policy) - Some lists are policy-based (like Spamhaus PBL for dynamic IPs). These aren't accusations of wrongdoing.
Listed (Spam) - IP associated with spam. Requires investigation and remediation before delisting.
Listed (Exploit) - IP showed malicious behavior (botnet, malware). Usually auto-removes after traffic stops.
Try It Now
Enter any IP address in the search box above, or check these examples:
Related Tools
RBLS focuses on email reputation. For other network tools:
- DNS Ninja - Fast DNS lookups including MX, SPF, DKIM, and DMARC records
- RTSAK - BGP routing and AS number analysis
- HashXP - Bitcoin and Lightning Network explorer
API & SDK
All RBLS data is available programmatically:
- TypeScript SDK —
npm install @robtex/sdk— IP reputation, blocklists, DNS intelligence - REST API — free tier, no key required
- RapidAPI — managed billing, plans from $19/mo
- MCP Server — for AI agents (Claude, ChatGPT, Grok)