Re: [9fans] spam filtering (again)

[geoff@collyer.net]

validatesender isn't doing challenge/response, though I use that too.
It's just insisting that the nominal MAIL FROM:<> address be valid,
unless you've exempted it explicitly.  I guess my reponse to the web
page is that it's my inbox, so I'm justified in controlling what lands
in it.  I'm also paying for the bandwidth into my house, so I'm
justified in preventing spam from crossing my DSL line.
validatesender works really well (I had to watch the smtpd logs at
first, but I tend to do that anyway), and challenge/response as
implemented by presotto in pipeto (what I call pipeto.token) works
well too.

Actually the `next step' protocol I'm talking about is not RSMTP; I
think that one is stuck in the wheels of the patent office and they've
stopped turning.  I call this new one NSTP (non-spam transfer
protocol) and it includes some properties of RSMTP but is a new
protocol.  It's also not finished and I haven't found anyone who wants
to pay me to finish it and implement it yet.