exim problems: relaying denied
ok i am new to exim. anyway, anyone can send mail from a local address, to a local address finebut when a user tries to send mail from a local address to any other address they get a releaying denied error

here is what the top of my exim conf looks like
domainlist local_domains = thedigitaldream.co.uk : crystalphase.com : team-zenturion.com : zen-network.com
domainlist relay_to_domains =
hostlist relay_from_hosts = 127.0.0.1 : 192.168.0.0/16
192.168.0.0/16 is there because there are several pc's on a lan with this server
any idea as to what is wrong?
thanx