On Tue, Nov 24, 2009 at 11:50:54AM -0500, Brad Laue wrote:
Exclusionary blocklists are a great idea if they're constantly maintained. I'm unclear as to why mail administrators don't work more proactively with things like SenderID and SPF, as these seem to be far more maintainable in the long-run than an ever-growing list of IP address ranges.
Because SenderID and SPF have no anti-spam value, and almost no anti-forgery value. Not that this stops a *lot* of people who've drunk the kool-aid from trying to use them anyway, but blacklists are still -- by a huge margin -- the most effective anti-abuse tool available. That said, blacklists (like all such resources) should be maintained, and those using them should provide working contact methods that enable resolution of the inevitable mistakes. The problem thus isn't so much the choice of/use of blacklist(s), it's incompetent mail system administration. ---Rsk