Any possible way to DOS this setup

[Chuck]

I have obtained a list (quite long) of domains used by known
spammers.. (send a single reply to me only and I will send a URL where
this can be obtained if you're interested) I want to alias each of
these in /etc/hosts and point them to my loopback, (127.0.0.1) so
return traffic goes nowhere. Does this introduce any means for DOS
attacks that aren't already present in a typical mail/web server? I
don't want to bog down iptables anymore than I already have. (I have
tons of explicit single-IP blocks to include nearly every network
originating in china, russia, and india) I've been doing heavy solaris
stuff for the past 3 years and I haven't kept up with Linux as well as
I would have liked to. Currently we are running RHEL 4.

Thanks for any info.
/cc


-- 
Chuck Carson - Sr. Software Engineer
Galileo Educational Solutions