Free IP Blacklist Checker

Check whether an IP address is listed on any of 12 major DNS-based blacklists (DNSBLs) used by email providers worldwide. If your emails are bouncing or landing in spam, a blacklisted IP is often the cause. This tool checks all 12 lists simultaneously and tells you where you stand.

How to Use This Tool

1. Enter an IP address – type or paste any public IPv4 address. Leave it empty to check your own IP. If you’re checking a mail server, enter the IP that your outbound email is sent from (check your email headers or ask your hosting provider).
2. Click “Check” to query all 12 blacklists simultaneously. Each check is a DNS lookup against the blacklist’s zone, so results return within a few seconds.
3. Review the results. Each blacklist shows a clear pass or fail status. If your IP is listed, the tool identifies which specific list flagged it and provides a link to that blacklist’s website where you can request delisting.

Understanding Your Results

The tool checks your IP against these 12 widely-used blacklists:

How to interpret the results:

• All clear – your IP isn’t listed on any of the 12 blacklists. Email delivery shouldn’t be affected by IP reputation.
• Listed on 1-2 minor lists – may cause occasional delivery problems with specific providers. Request delisting through the links provided.
• Listed on Spamhaus or multiple lists – this will cause significant email delivery failures. Investigate the root cause (compromised server, misconfigured mail relay, spam from a user on your network) before requesting delisting, or you’ll be relisted quickly.

Why This Matters

Email blacklists are the internet’s reputation system for mail servers. When your IP address appears on a blacklist, email providers that subscribe to that list will either reject your emails outright or route them to spam. Since most major email providers check at least Spamhaus and one or two other lists, a single listing can cut off your email delivery to a large portion of the internet.

The tricky part is that blacklisting can happen without you doing anything wrong. If you’re on shared hosting, another customer on the same server sending spam can get the shared IP blacklisted – and your emails suffer too. If your website or server is compromised, attackers often use it to send spam before you even notice the breach. And if you’ve recently moved to a new IP address, it may carry the reputation of its previous user.

Regular blacklist checks are especially important if you run a business that depends on email – transactional emails (order confirmations, password resets, invoices) are just as affected as marketing emails. If your customers aren’t receiving their receipts, checking your IP against blacklists is one of the first troubleshooting steps.

Frequently Asked Questions

My IP is blacklisted – how do I get delisted?

Each blacklist has its own delisting process, and the tool provides direct links to each one. The general steps are: first, identify and fix the root cause (compromised account, open relay, malware on a device on your network). Then, visit the blacklist’s website and submit a delisting request. Some lists (like SpamCop and PSBL) auto-delist within 24-48 hours after the spam activity stops. Others (like Spamhaus) require you to submit a removal request and may ask for evidence that the problem has been resolved. Don’t request delisting until you’ve fixed the underlying issue – repeat listings are harder to remove.

Why is my home IP address on the RATS Dyna list?

The RATS Dyna list specifically targets dynamically assigned IP addresses – the kind your home internet provider gives you. This isn’t necessarily a problem. The list exists because legitimate mail servers should run on static IP addresses, not residential connections. If you’re running a mail server from home (which most ISPs prohibit in their terms of service), this listing will cause delivery problems. If you’re simply sending email through your provider’s mail servers or a service like Gmail, your home IP being on RATS Dyna doesn’t affect your email delivery because your emails are sent from your provider’s servers, not directly from your home IP.

How often should I check my mail server’s IP?

For production mail servers: weekly at minimum, daily if you’re sending high volumes. Many email administrators set up automated monitoring that alerts them immediately if their IP appears on a blacklist. The sooner you catch a listing, the faster you can fix the underlying issue and request delisting – and the less email you lose in the meantime.