SURBLs are lists of web sites that have appeared in unsolicited messages. Web sites almost always use domain names. Only rarely are IP addresses used as web sites. Web sites appearing as IP addresses are often cracked phishing or malware sites.
SURBLs are not lists of mail servers, mail senders, email addresses, open proxies or message sending IP addresses. They are lists of web sites.
Please enter IP addresses in normal forward octet order such as 10.20.30.40. They will be checked and displayed in reverse octet order such as 22.214.171.124. This is a traditional way that IP addresses are represented in blacklists.
Please do NOT use this web site for any automated lookups. Instead use DNS queries as described in the SURBL Implementation Guidelines.