Setting up SMTP?

[Shane Presley]

Hello,

I just installed Fedora, and installed Big Brother for network
monitoring.  This is my first time setting up linux, so sorry for a
newbie question.

I need the server to have SMTP running, so that users in our network
can send e-mails to the server, which will fire off a script to deal
with the e-mail.  For example an admin wants to acknowledge an alert,
he sends mail to bb at mylinuxbox.mydomain.com.

Initially SMTP wasn't running on my box.  So I just ran
/etc/rc3.d/S80sendmail start.  Okay now sendmail appears to be
running.  ps -aef | grep sendmail shows

root      1725     1  0 Oct25 ?        00:00:00 sendmail: accepting connections
smmsp     1734     1  0 Oct25 ?        00:00:00 sendmail: Queue
runner at 01:00:00 for /var/spool/clientmqueue

But if I telnet to port 25 on my system, I get connection refused. 
There is no firewall.

I assume I need to change something in my sendmail config?  I read the
Red Hat Linux Reference Guide and I couldn't really figure out what I
need to change.  I was a little concerned about this section:

dnl #
dnl # The following causes sendmail to only listen on the IPv4 loopback address
dnl # 127.0.0.1 and not on any other network devices. Remove the loopback
dnl # address restriction to accept email from the internet or intranet.
dnl #
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

But I'm not sure if I should comment that out. Also I tried to build a
new sendmail.cf file and got this error:

m4 /etc/mail/sendmail.mc > /etc/mail/sendmail.cf
/etc/mail/sendmail.mc:10: m4: Cannot open
/usr/share/sendmail-cf/m4/cf.m4: No such file or directory

So I guess I need help with what I have to modify to get sendmail
running?  And if I need to modify sendmail.mc, then I need help with
how to build sendmail.cf?

Note - this system will be on the intranet.  Not internet accessible.  

Thanks,
Shane