Posted by Virus Bulletin on Jan 24, 2012
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. The document summarises best practices both for running such lists and for the use of them by mail server administrators. These practices include having the criteria for listing and delisting easily available and responding quickly to removal requests, as well as a number of more technical practices.
Perhaps most controversially, the document advises users of DNSBLs to avoid those that charge fees for delisting or faster handling of such requests. It says such practices easily lead to accusations of blackmailing and extortion. Even if unjustified, such accusations could still damage the reputation of the DNSBL and perhaps the DNSBL mechanism as a whole.
The document, which represents the consensus of the Anti-Spam Research Group (ASRG) within the Internet Research Task Force (IRTF) and which has been given RFC number 6471, can be found here.
Posted on 24 January 2012 by Virus Bulletin