The IP address blacklist check will show if the URL or IP entered consequently listed with DNSBL or SURBL systems. These systems uniquely used by email system administrators to try and eliminate spam email messages before they reach their users. For example, mainly if a company uses email marketing, an IP blacklist is something to try to avoid. IP address blacklisting occurs when your IP address (or the IP address you share with others) ultimately ignored by a web hosting company. To clarify, any email you try to send consequently blocked and not forwarded. This can easily be found out with using our IP address blacklist check.
IP Address Blacklist Check Databases
DNSBL is a Domain Name Blacklist
There are dozens of DNSBLs online, all of which use a wide variety of criteria for listing and delisting addresses. Spam filters utilize various DNSBLs to verify that the incoming emails do not originate from blacklisted sites. DNSBLs are generally the first line of defense against spam.
SURBLs(no longer an acronym)
These IPs are generally the second line of defense but not all spam filters are capable of using them. Blacklists of websites are SURBLs when appearing in unsolicited emails. Spam filters that can utilize the SURBLs will scan the body text of emails and extract any website addresses and check them against the blacklists. If found an address, the message appropriately flagged as spam and handled accordingly.
Since both methods filter differently they are most effective when combined. Unfortunately as spammers become more clever there isn’t a method that can catch every spam message. It is interesting to note, given the methods spammers use, that DNSBLs tend to change more frequently than SURBLs. If you’re an email system administrator and your server has been blacklisted, you will have to work with the various DNSBLs that may have you listed and/or SURBL (http://www.surbl.org/).