DNSBL settings problems in Sendmail ?

[rob.c]

DNSBL settings problems in Sendmail ?

FreeBSD 4.7 and 4.8
Sendmail 8.12.6p2/8.12.9

I have my sendmail configured to check mail against multiple DNS based black
lists, however this doesn't seem to block any mail. Each time i get a UCE i
check the spammers mail server IP against the lists that i'm using and in
each case the message should have been blocked.
An example of one of my sendmail.mc lines is:
FEATURE(dnsbl, `Spews.relays.OsiruSoft.com', `"550 Mail from "
$&{client_addr} "
rejected, see http://relays.osirusoft.com/ " $&{client_addr}')

I don't see any rejections like this in /var/log/maillog.

Could somebody point my to the right FAQ manual ? I can't find anything
related on sendmail.org about verifying whether dnsbl is working or on
devshed forums.

thanks in advantage for any assistance,
rob