Tag: dnsbl

  • We are more ready for IPv6 email than we may think

    In email security circles, IPv6 is the elephant in the room. While the transition from IPv4 to IPv6 is a relatively smooth affair for most of the Internet, and few people will have noticed that a large part of Internet traffic is currently using IPv6, email is still lagging behind: RIPE, Europe’s Regional Internet Registry,…

  • We are more ready for IPv6 email than we may think

    In email security circles, IPv6 is the elephant in the room. While the transition from IPv4 to IPv6 is a relatively smooth affair for most of the Internet, and few people will have noticed that a large part of Internet traffic is currently using IPv6, email is still lagging behind: RIPE, Europe’s Regional Internet Registry,…

  • Expired domain led to SpamCannibal’s blacklist eating the whole world

    The first line of defence in many a spam filter is to query one or more DNS blacklists to see if the sender’s IP address (and sometimes their domain) is listed as a known spammer. As the name suggests, a DNS blacklist is queried over DNS: to do a lookup for the IP address 1.2.3.4…

  • Expired domain led to SpamCannibal’s blacklist eating the whole world

    The first line of defence in many a spam filter is to query one or more DNS blacklists to see if the sender’s IP address (and sometimes their domain) is listed as a known spammer. As the name suggests, a DNS blacklist is queried over DNS: to do a lookup for the IP address 1.2.3.4…

  • Kelihos checks machines’ IP addresses against DNS blacklists

    Role of node in a botnet dependent on whether the IP address is blacklisted. Whenever I look at the results of the VBSpam tests, it always amazes me how large a percentage of spam is blocked because the sending IP address appears on a DNS blacklist. It is not that I wouldn’t expect those that…

  • New RFC describes best practices for running DNS-based lists

    DNSBL users advised to avoid those lists that charge for delisting. A new RFC document has been published that describes the best operational practices for the use of DNS-based lists in email filters. DNS-based lists (somewhat confusingly called ‘DNSBLs’ in the document) include blacklists and whitelists of IP addresses, but also URIBLs and geographical-based lists.…