[Exim] need hosts_randomize syntax example

Can somebody give an example of using the hosts_randomize option. It looks
like you can do it either as a domainlist router, or an smtp transport.

I want to list a bunch of machines (mail, mail2, mail3, etc) and have
portions of a mailing list go to different smarthost machines for final
delivery. So that a message to 100,000 people on a mailing list is
distributed evenly amongst all listed machines.

For example, I currently have something like this

n_thru_p_domains:
    driver = domainlist
    transport = one_hundred_smtp
    self = fail_soft
    host_find_failed = fail_soft
    route_list = "^[n-p] mail.internet-tools.com: mail2.internet-tools.com
bydns_a"

I want to put a hosts_randomize clause in there, in place of the route_list
I think, but I can't figure out the syntax.

Thanks in advance for any help.

mark

mark david mcCreary
Internet Tools, Inc.            1436 West Gray #438
mdm@???          Houston, Texas 77019
http://www.internet-tools.com   713.627.9600