Email Blacklist Checker
Check your email sending IP or domain against more than 100 real-time email blacklist servers.
What is an Email Blacklist (DNSBL)?
An email blacklist (DNSBL) is a real-time database that acts as a “digital bouncer” for your inbox. It identifies IP addresses or domains linked to spam activity. ISPs like Gmail and Outlook use these to decide if your email is trustworthy or should be blocked entirely.
Not All Blacklists Are Created Equal
There are over 100 blacklists, but their impact on your deliverability varies wildly. Understanding which one you are on is the first step to fixing the problem.
| Type | Example | Impact Level |
|---|---|---|
| Major RBLs | Spamhaus, Barracuda | Critical (Full Block) |
| ISP-Specific | Gmail, Microsoft Senders | High (Spam Folder) |
| Niche Lists | LashBack, Sorbs | Low (Warning) |
The “Listed” Protocol: How to Get Off a Blacklist
If our tool shows you are listed, don’t panic. Follow this protocol to restore your sender reputation:
- Identify the Root Cause: Check for security breaches, high bounce rates, or spam complaints.
- Fix the Issue: You cannot request delisting until the problem (e.g., an open relay or malware) is resolved.
- Request Delisting: Visit the RBL’s website and look for a “Removal” or “Lookup” page. Most lists offer a self-service removal for first-time offenders.
- Warm Up Gradually: After delisting, don’t resume high-volume sending immediately. Re-warm your IP to show ISPs you are a stable sender.
Common Reasons for Blacklisting
High Spam Complaints
Exceeding a 0.1% complaint rate is a “red flag” for ISPs and will trigger a listing almost instantly.
Spam Traps
If you send to a “Honeypot” (an email address created solely to catch spammers), you will be blacklisted automatically.
Sudden Volume Spikes
Going from 0 to 10,000 emails in a day looks like a bot attack. Gradual warming is the only safe way.
Technical Misconfiguration
Missing PTR (Reverse DNS) records or incorrect SPF/DKIM setups can lead to “False Positive” listings.
Action plan
Audit your email infrastructure
Get a full deliverability scorecard and technical setup review to prevent future listings.
Take the AssessmentAutomated Blacklist Monitoring
Warmup Inbox monitors your domain 24/7 and alerts you the second you hit a blacklist.
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