IP Blacklist Check
Check whether an IPv4 address appears on any of 46 major DNS-based blacklists (DNSBL). Blacklisted IPs can have email delivery issues and may be blocked by security systems. Only IPv4 is supported - IPv6 DNSBL coverage is not yet standardised.
DNSBL Category Guide
Different blacklists focus on different types of abuse. Understanding which list flagged your IP helps you determine the right remediation step.
| Category | What It Checks | Common Impact |
|---|---|---|
| Spam | IPs that have sent unsolicited bulk email or spam. | Email rejected or sent to junk folder. |
| Abuse | IPs associated with network abuse, malware, or botnets. | Blocked by firewalls and mail servers. |
| Proxy / Tor | Known open proxies, SOCKS proxies, and Tor exit nodes. | Blocked by services that prohibit anonymous access. |
| Dialup / Dynamic | Residential dynamic IP ranges not expected to send email directly. | Outbound email should use an ISP relay or SMTP service. |
| General RBL | Broad real-time block lists combining spam and abuse signals. | Email delivery failures and web access restrictions. |
How to Get Delisted
- Identify the specific DNSBL(s) where your IP is listed.
- Visit each list's website and look for a removal or delist request form.
- Scan your systems for malware or spam-sending software before requesting removal.
- Contact your ISP if your IP block was listed due to a neighbour's activity.
- Some lists auto-expire listings after 24–72 hours if no new abuse is detected.