Re: [ietf-smtp] the point of domain authentication

[Sam Varshavchik <[e-mail]>]

John R Levine writes:

> For some reason, much of the IETF is particularly disconnected from e-mail  
> reality.  I know IETFers who claim that DNSBLs were a fad in the 1990s and  
> nobody uses them any more.

I subscribe to a combination of:

1) That public DNSBL usage are reasonably popular. Everyone from Microsoft  
(Outlook/Office365) to various hosting providers (1and1/godaddy) to large  
infrastructure providers (GTT) uses public DNSBLs.

2) That their golden age was in the 1990s. These days they'll mostly block  
an occasional spam, but the don't amount to more than a rounding error of  
the massive crapton that's flying everywhere.

Occasionally I hear someone say that they see public DNSBLs blocking a  
significant portion of the crap. That's certainly possible, of course, but I  
believe that's an outlier. Everyone's incoming E-mail is unique. So it's not  
unexpected that, for some, DNSBLs will have some level of effectiveness. But  
I have reasons to doubt that they amount to much for most end recipients.