Blocklists

Overview The URIBL blocklist lists domains appearing in spam and is used with anti-spam software such as SpamAssassin. It does not list domains from where a message was sent. It has five publicly available lists representing different levels of se...

Overview The Truncate blocklist identifies potential sources of spam, scams, viruses, and malware by monitoring IP reputation data from systems using the Message Sniffer spam and virus protection software.  Listings occur at the IP level. The imp...

Overview The SPFBL blocklist identifies potential sources of spam using reputation data collected from a customer and contributor network. It is primarily used in third-party spam filter software. Listings occur at the IP and domain level. The im...

Overview SpamRATS! is a real-time blocklist used to identify spam originating from botnets and compromised servers. Listings occur at the IP level. The impact on deliverability is low. Reasons for getting listed Your IP address may be listed if ...

Overview The NoSolicitado blocklist uses a pristine spam trap network and other techniques to identify potential sources of spam, phishing, and email scams. Listings occur at the IP level. The impact on deliverability is low. Reasons for getting...

Overview The HostKarma blocklist uses spam traps along with other spam detection techniques to identify potential sources of spam. Listings occur at the IP level. The impact on deliverability is low. Reasons for getting listed Your IP address ma...

Overview The Cloudmark CSI blocklist is owned an operated by Proofpoint. It uses a combination of techniques to identify possible sources of spam using data from the Cloudmark Global Threat Network. Listings occur at the IP level. The impact on d...

Overview The 0Spam blocklist uses spam traps and other spam reporting services to identify possible sources of spam. Listings occur at the IP level. The impact on deliverability is low. Reasons for getting listed Your IP address may be listed if...

Overview The Spamhaus Domain Block List (DBL) is a list of domains of spam sources, including known spammers, spam gangs, spam payload URLs, spam sources and centers ("right-hand side"), and phish, virus and malware-related sites. Listings occur ...

Overview The Return Path Blocklist (RPBL) from Validity algorithm identifies indicators of spam and abusive behavior from IPs, such as botnets, suspicious payloads, and those failing authentication. This blocklist is used by mailbox providers, se...

There is no difference between a blocklist and blacklist, and the terms are often used interchangeably across the email industry. Over the years, industry leading blocklist providers such as Spamhaus, Spamcop, Barracuda, and Validity decided to us...

There are hundreds of blocklists available, but not all blocklists are created equal. Because anyone can start a blocklist, a lot of them are not widely used by mailbox providers. This makes it difficult for a sender to know when to be concerned a...

Overview The Composite Blocking List (CBL) is a Domain Name System (DNS)-based blocklist. It includes email services suspected of sending spam as a result of a virus or malware infection. The CBL gets its data from large Simple Mail Transfer Proto...

Overview SpamCop is a spam reporting service that takes reports of spammers’ IPs addresses from recipients. It uses the information to maintain the SpamCop Blocking List (SCBL). SpamCop also generates reports of email sent to spam traps. It uses p...

Overview The Weighted Private Block List (WPBL) lists IP addresses that connect to WPBL members' systems and send spam. WPBL listings occur at the IP address level. This blocklist has a small impact on deliverability. The WPBL is used globally. ...

Spamhaus is an international blocklisting organization that was founded in Europe in 1998 to track spammers and spam-related activity. Spamhaus compiles and distributes six Domain Name System (DNS)-based blocklists (DNSBLs) and one domain-based bl...

Overview The Spamhaus Block List (SBL) is a list of IPs of spam sources, including known spammers, spam gangs, spam operations, spam support services or has sent unsolicited email to the Spamhaus trap network. Listings occur at the IP level. The ...

Overview The Spamhaus Policy Block List (PBL) is a list of all dynamic IP addresses and some static IP addresses, and is not specifically a blocklist. IPs on the PBL are not listed for sending spam or for anything they have done. For example, the ...

Overview The Spamhaus Composite Snowshoe (CSS) blocklist uses proprietary data to identify IPs with low reputations that send snowshoe spam, or spam from compromised hosts. This blocklist is a component of the Spamhaus Block List (SBL). Listings ...

Overview The Spamhaus Exploits Block List (XBL) is a list of known open proxies and illegal third-party exploits that are used to send spam and viruses. It includes information gathered by Spamhaus and contributing Domain Name System blocklist (DN...

Overview The Spam Uniform Resource Identifier Real-time Block List (SURBL) is a collection of public lists that identify Uniform Resource Identifier (URI) hosts, typically websites, that have appeared in unsolicited email messages. SURBL lists sea...

Overview LashBack's UBL includes the IP addresses of senders who send to email addresses harvested from a suppression list. Listings occur at the IP address level. The blacklist is updated hourly. The impact on deliverability is minimal and not v...

The Invaluement blocklist is made up of three commercial anti-spam blocklists. ivmURI: This lists URIs (including both domains and a few IP addresses) owned by spammers. ivmSIP: Spammy IP addresses either overlooked or not yet listed by Spamhaus,...

Overview The Spam and Open Relay Blocking System (SORBS) Open Proxy blocklist is a list of proxy servers that allow anyone to connect regardless of identity or authentication. Allowing anyone to connect to the proxy server permits an attacker to s...

Overview The Spam and Open Relay Blocking System (SORBS) DNSBL blocklist is a Domain Name System-based Block List (DNSBL). This blocklist is SORBS’ aggregate blocklist that blocks email from host servers known to distribute spam, phishing attacks,...

Overview The Spam and Open Relay Blocking System (SORBS) Dynamic User and Host List (DUHL) blocklist includes subnets that reject email from entire ranges of IP addresses. This includes hosting companies that send spam as well as single IP address...

Overview The Spam and Open Relay Blocking System (SORBS) HTTP blocklist is a list of open Hypertext Transfer Protocol (HTTP) proxy servers. Listings occur at the IP level. The impact on deliverability is low. Reasons for getting listed IPs are b...

Overview The Spam and Open Relay Blocking System (SORBS) Web blocklist identifies web servers that have unsecure email sending scripts which can be exploited to send spam email. The blocklist blocks email from host servers known to distribute spam...