Free Email Blacklist Checker a.k.a. Spam Database Lookup
Check 50+ email blocklists for your IP or domain in one real-time scan — with per-listing remediation links.
How It Works
Enter your IP or domain
Type the IP address or domain you want to check. The tool accepts both — you don't need to specify which.
We scan 50+ blocklists
Your query runs in real time against the major databases used by Gmail, Outlook, Yahoo, and other mailbox providers — Spamhaus, Barracuda, SORBS, SpamCop, UCEPROTECT, and more.
Act on the listings
For each listing, follow the remediation link to submit a delisting request with that operator. Most process removals within 24–48 hours.
What is a spam database lookup?
A spam database lookup checks whether an IP address or domain appears on any of the email blocklists that mailbox providers consult before accepting mail.
Blocklists (also called blacklists, DNSBLs, or RBLs) are real-time reputation databases run by anti-spam organizations. When a recipient's mail server receives a message, it can query these databases to decide whether to accept, reject, route to spam, or throttle the sender. A single listing on a major blocklist like Spamhaus or Barracuda can drop your inbox placement by 30–70% overnight. InboxAlly's free Spam Database Lookup scans 50+ blocklists in one pass and surfaces the remediation steps for each operator that has flagged you. Used together with sender reputation, SPF, and DMARC, it's the standard set of free diagnostics for anyone seeing unexplained deliverability problems.
Why Scan for Blocklisting?
Protect your sender reputation
A single Spamhaus or Barracuda listing can drop your inbox placement by 30–70% within hours. Catching a listing the day it happens — instead of weeks later when your open rates collapse — is the difference between a quick fix and a months-long recovery.
Avoid sudden deliverability cliffs
Most senders don’t realize they’re blocklisted until campaign metrics tank. Running a blocklist check before every major send (and after any sender-reputation event like a deliverability dip) catches issues before they hit your real subscribers.
Catch authentication failures early
Get a 50+ database scan in one pass
Most free blocklist tools check 5–10 databases. We scan 50+ — including all four Spamhaus zones (SBL, XBL, PBL, DBL), Barracuda BRBL, SORBS, SpamCop, UCEPROTECT (L1/L2/L3), Invaluement, PSBL, and many others. A single scan tells you the full picture.
Understanding the Major Blocklists
Directly consulted by Gmail, Outlook, Yahoo, and most enterprise filters. A listing here typically drops your inbox placement by 30–70% within hours. Treat any listing as urgent and start the delisting workflow immediately.
Used by mid-tier ISPs and self-hosted mail servers. Less catastrophic than Spamhaus, but accumulating listings here is a strong signal something is wrong with your sending pattern — fix the underlying cause before pursuing delistings.
Specialized or niche lists used by smaller filters. Low immediate impact on deliverability, but a listing pattern across multiple watch-list databases often precedes a Spamhaus or Barracuda listing — treat them as early warning indicators.
Spam Database Lookup FAQ
What is a spam database lookup?
A spam database lookup checks whether your IP address or domain appears on any email blocklist. Blocklists are maintained by anti-spam organizations and used by mailbox providers like Gmail, Outlook, and Yahoo to decide whether to accept, reject, or filter incoming email. InboxAlly's tool scans 50+ databases simultaneously and shows your status on each one.
How do I check if my IP address is blocklisted?
Enter your IP address into InboxAlly's Spam Database Lookup tool. The tool queries 50+ major blocklist databases in real time and reports which lists your IP appears on. No signup or account is required.
What blocklist databases does this tool check?
The tool scans over 50 blocklist databases including Spamhaus (SBL, XBL, PBL, DBL), Barracuda Reputation Block List, SORBS, SpamCop, UCEPROTECT (Levels 1-3), Invaluement, PSBL, and many others. Both IP-based and domain-based lists are covered.
What should I do if my IP or domain is blocklisted?
First, identify the root cause — common reasons include sending to spam traps, high complaint rates, compromised servers, or poor list hygiene. Then visit the blocklist operator's website to submit a delisting request. Most operators process requests within 24-48 hours. Finally, fix the underlying issue to prevent re-listing.
How does blocklisting affect my email deliverability?
When your IP or domain appears on a blocklist, mailbox providers may reject your emails outright, route them to the spam folder, or throttle your sending. The impact depends on which blocklist you appear on — Spamhaus and Barracuda listings are particularly damaging because they are widely referenced by major mailbox providers.
Can I check a domain instead of an IP address?
Yes. The tool supports both IP address and domain lookups. Domain-based blocklists (DBLs) flag domains that appear in spam messages, phishing emails, or malware distribution — even if the sending IP itself is clean.
How often should I check my blocklist status?
Check proactively before major email campaigns and whenever you notice a sudden drop in open rates or increase in bounce rates. For ongoing monitoring, InboxAlly's paid platform provides continuous blocklist monitoring with real-time alerts when a new listing is detected.
Why am I on a blocklist if I don't send spam?
Common reasons include sending to purchased or scraped lists that contain spam traps, shared hosting where another sender on the same IP was flagged, compromised email accounts, high bounce rates from outdated lists, or DNS misconfigurations. Blocklists flag behavior patterns, not intent.
What is the difference between an IP blocklist and a domain blocklist?
IP blocklists flag the sending server's IP address based on sending behavior. Domain blocklists flag the domain name based on its association with spam content. You can be listed on one without being on the other, which is why checking both is important.
Is this tool really free?
Yes — the Spam Database Lookup is free to use with no signup, no credit card, and no account required. There are sensible rate limits in place to keep the tool fast and responsive for everyone, but no daily quota or paywall for normal use. It is one of several free deliverability tools offered by InboxAlly to help email senders diagnose and fix inbox placement issues.
Lookup Tells You Where.
InboxAlly Fixes Why.
Knowing you're on Spamhaus is step one. Earning back the reputation that keeps you off it — with the engagement signals mailbox providers reward — is what InboxAlly does next.
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Trusted by 20,000+ brands · SOC 2 aligned · founded 2019
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