Re: the point of domain authentication

It appears that Sam Varshavchik  <[email protected]> said:
>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.

Of course.  Big providers all have paid subscriptions that give then higher
query rates and often extra data.

>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.

Your mail must be very different from mine.  The handful of DNSBLs I use block the majority
of the incoming mail I get and from looking at the logs, the error rate is very low.

Large mail providers use DNSLBLs as part of their scoring systems.  I use a handful to do
simple blocking that I trust not to overblock (Spamhaus, Invaluement) but large systems have
a lot more complicated mail flows than we do.

R's,
John