Note: It takes 20 to 40 seconds to check blacklists.
Check to see if any IP address or an email server IP is blacklisted or not with over fifty plus DNS-based blacklists (DNSBLs). It helps to identify IP reputation and email spam.
The tool checks whether the given URL, IP address, or email server's IP is listed with DNSBL. Email system providers utilize that database to filter out spam emails before they finally reach the end-users.
For example, if your company uses email marketing and you send out thousands of emails to promote your new product, some of the receivers mark that email as spam. There is a high chance that your IP will be on the IP blacklist, which needs to be avoided.
IP address blacklisting is the process or method to filter out or block the illegitimate or malicious IP addresses to access your network. It occurs when a web hosting company ultimately ignores your IP address. More precisely, any email you try to send is consequently blocked and filtered as spam.
One estimate concludes that email traffic consists of 80% of spam emails. That overwhelming amount of commercial emails lead to strict blacklisting practices to keep the inboxes spam-free.
DNSBL stands for Domain Name System Blacklist, is the blacklist that allows the administrator to block the messages from specific IP that has a history of sending spam messages. The list is based on Internet's Domain Name System, which converts the IP address into the domain name, and makes it much easier to understand.
Suppose a maintainer of a blacklist in the past has received any spam from a specific domain. It would include that server in its blacklist. All the messages sent from that particular server would either be rejected/flagged by all the websites that use that blacklist to avoid spam. DNSBL is the first line of defense.
There are dozens of DNSBLs available online, and each one has its own set of rules and offensive categories to focus on. The most common nasty type is spam, but some blacklists focus more on hacking, malware, botnets, etc. The email administrators use these DNSBLs to check if the incoming email is generated or originated from the blacklisted IP address or not.
SURBL is a list of websites that have appeared in unsolicited messages. It is the second line of defense, but not all the spam filters can use it.
With time the spammers become pretty intelligent, and there is no proper way to catch every spam message. The email administrators use the SURBLs to scan the email messages' body text to extract any website address present and check it against the blacklists. If found any address, the message would be treated either as spam or handled accordingly as per the instructions.
Note: It is interesting to note that the websites in unsolicited messages are consistently used than the rapidly changing botnet IP addresses used to send the vast majority of them. If you are from an email marketing company, running an email advertisement, or from an email system administrator and your IP has been blacklisted, then you have to work with various DNSBLs and SURBLs to delist your IP address.
The process is simple.
A blacklist is a database of IP addresses that are believed to send spam. Emails from these IP addresses are either blocked or routed to the recipient's spam folder or handled accordingly.
Your IP may be in a single blacklist or multiple backlists. There is no centralized authority for that. Each blacklist is managed independently, and each has its criteria for listing or delisting the IP address in its blacklist.
There are several reasons that your IP is on the blacklist.
Several online tools and websites are free and check that the given URL, IP address, or email server IP is consequently listed with DNSBL or SURBL systems.
Note: We do not manage, run, or have any direct affiliation with any blacklist. We are only providing a single platform to check an IP address's status on third-party blacklists. We do not recommend using any specific blacklist and do not condone blacklists that require payment for removal. The inclusion of such blacklists is for completeness and should not support that blacklist's usage.