Spamhaus...

[johnl at iecc.com (John Levine)]

>When we licensed Spamhaus a few years back, they required us to
>set-up a DNS slave server instead of querying against their public
>server. They had a special DNS client that allowed partial zone
>updates. Turns out we downloaded huge hourly updates.

They now give you the choice of rsync or queries to non-public
servers.  Unless you have a humungous mail system, queries are cheaper
and certainly less hassle.

>We no longer use Spamhaus, relying instead upon Sender Base Reputation 
>Scores (IronPort).

How does the price compare?

R's,
John