sendmail & realtime blackholes?

[Darin Perusich]

does anyone have experience setting up sendmail, or any other MTA for
that matter with the Mail Abuse Prevention System's Realtime Blackhole
List from mail-abuse.org? it's simple enough to configure sendmail to
use it, just add FEATURE(dnsbl) to your sendmail.mc before you run m4
against it, this i've done. i'm trying to test the feature and it
doesn't appear to be doing the lookup. instructions are located at
http://www.mail-abuse.org/rbl/usage.html#DNSuse and it should be really
straight forward. 

something else that i'm finding bizarre, when i do an nslookup on
blackholes.mail-abuse.org the lookup fails. regardless of what name
server i use, unless i use the mail-abuse.org name server which tells me
there are 3 machines serving that host. now dns by it's nature should
just pass my lookup along until it locates the host, if it's configured
correctly .

anyone have any ideas?

-- 
Darin Perusich
Unix Systems Administrator
Cognigen Corp.
darinper at cognigencorp.com