[exim] how to implement a blacklist of IP addresses

Hello

I am using Exim 4.72 on Debian 6.0.6. I have dumped the Debian
configuration scheme and composed my own exim4.conf file based on the
sample supplied. I have successfully implemented a blacklist of sending
domains which works like this:

acl_smtp_mail = acl_check_mail
acl_check_mail:
  deny    message          = Domain blacklisted locally
          sender_domains   = lsearch;/etc/exim4/senderdomains.blacklist

where the file senderdomains.blacklist contains a list of this format:

dirtyspammers.org
spamserver.lots-o-spam.net
dishitout.spammers.com
etc

My question is how to do something similar with a list of IP addresses.
Would a similar structure be appropriate and where would it be put? Hope
this is not too easy.


Damien Moore