Check if an IP address or domain is listed on DNS-based blacklists (DNSBL/RBL). Scan across curated blacklist providers simultaneously, for IPv4 and IPv6. Free, no sign-up required.
The reportedIP DNSBL Checker tests an IP address or domain against a curated set of DNS-based blacklists in parallel and links each listing directly to the operator’s delisting process — a listed mail server is the most common reason legitimate email lands in spam.
DNS-based Blackhole Lists (DNSBLs), also known as Real-time Blackhole Lists (RBLs), are databases of IP addresses associated with spam, malware, or other malicious activity. Mail servers and security systems query these lists in real-time to decide whether to accept, reject, or flag incoming connections.
Being listed on a DNSBL can severely impact your email deliverability and server reputation. Our tool checks your IP address against a curated set of blacklist providers simultaneously, every list on it has been verified to answer reliably from public resolvers, giving you a dependable overview of your IP reputation.
Email-focused DNSBLs like Barracuda, SpamCop, and PSBL track IP addresses known to send spam or phishing emails. Being listed here directly impacts your email deliverability across major providers.
Security-focused lists like DroneBL, Blocklist.de, and S5H track IP addresses involved in malware distribution, botnet activity, or exploitation attempts. These lists protect networks from known threats.
Policy-based lists like the UCEPROTECT network levels flag IP ranges that should not be sending email directly, such as residential IP addresses or dynamic IP pools. These are not indicators of abuse but of policy violations.
1. Enter an IP address or domain: Type any IPv4 or IPv6 address, or a hostname, to begin the blacklist scan. A domain is resolved to both its A and its AAAA record, and both addresses are checked.
2. Reverse DNS lookup: The address is reversed and queried against each blacklist’s DNS zone (e.g., 4.3.2.1.bl.spamcop.net). An IPv6 address is expanded to all 32 nibbles first, the form RFC 5782 prescribes.
3. Parallel scanning: All blacklist queries run simultaneously for fast results. For an IPv6 address only the lists that actually run an IPv6 zone are queried, the others are listed separately instead of being counted as a clean result.
4. Result interpretation: A positive DNS response means the IP is listed. We decode the return codes to show the specific listing reason.
5. Delisting guidance: For each listing found, we provide information about the blacklist and guidance on how to request removal.
Identify the root cause: Before requesting removal, determine why your IP was listed. Common causes include compromised accounts sending spam, misconfigured mail servers, or malware infections.
Fix the underlying issue: Remove malware, secure compromised accounts, update software, and implement proper email authentication (SPF, DKIM, DMARC). Blacklists will relist you if the problem persists.
Request removal: Most blacklists offer a self-service delisting process. Visit the blacklist’s website and follow their removal procedure. Some lists automatically delist after a period of no further incidents.
Monitor regularly: After delisting, continue to monitor your IP reputation. Use this tool periodically to ensure you remain clean across the covered blacklists.
Prevention tips:
• Implement rate limiting on your mail server
• Use strong passwords and enable 2FA for all email accounts
• Keep your server software and CMS up to date
• Monitor outbound email traffic for anomalies
• Set up reverse DNS (PTR record) for your mail server IP
It means your IP address has been flagged for suspicious activity such as sending spam, distributing malware, or being part of a botnet. This can affect your ability to send emails and may indicate a security compromise.
For mail servers, check weekly or after any security incident. For web servers, check monthly. Set up automated monitoring if you manage critical infrastructure.
Yes. If your IP was previously used by someone who engaged in abuse, the listing may carry over. Shared hosting environments can also cause innocent users to be listed due to a neighbor’s bad behavior.
It varies by provider. Some blacklists process removal requests within hours, while others may take several days. A few lists automatically delist after a quiet period (typically 1-4 weeks).
These terms are often used interchangeably. DNSBL (DNS-based Blackhole List) is the technical name for the protocol. RBL (Real-time Blackhole List) was the original term coined by MAPS. “Blacklist” is the common informal term for all such lists.
Each blacklist is queried live over DNS. The set is curated: lists that refuse queries from shared or datacenter resolvers (such as Spamhaus ZEN) are excluded, because they would report false results rather than none. A list shown as “could not be queried” was unreachable — that does not mean the address is listed.
A domain is resolved to both its A and its AAAA record and both addresses are checked, because a mail server usually sends from either one. For an IPv6 address, only the lists that actually run an IPv6 zone are queried; the rest are shown separately instead of being counted as a clean result. Be aware that few public blacklists maintain meaningful IPv6 data so far. The ReportedIP community network check uses live reputation data from thousands of reporting servers and covers IPv6 in full.