limit e-mail outside

    Hello, I have installed sendmail 8.9.1a into a proxy server running
FreeBSD 2.2.7, this server connects my intranet with internet. The problem
is that I have configured two different networks and I want limit the access
to internet (don't send and receive) for a especific network but this
network could send and receive mail with the intranet. is it possible?, I
use procmail like local mail.


    Thanks in advance.