Replacing the xxx bits with the IP networks you want to allow relaying from
(your dialup lines in this case).
In the file allowed-relays put a list of all the domains that can relay
through you. In my example it is a partial- search with means you can put
stuff like *.somedomain.com in to allow somedomain.com and all its
subdomains. If you don't want this, lose the partial-.
If you want to use databases, change from the lsearch type.
