Setting up SMTP?

[Paul Howarth]

Shane Presley wrote:
> 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

Do "chkconfig sendmail on" to have sendmail start at boot time.

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

This is addressed in the Fedora release notes.

> 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.

You've found the right thing to change. Do as the comment says and change the 
DAEMON_OPTIONS line to:

DAEMON_OPTIONS(`Port=smtp, Name=MTA')dnl

 > 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

You need to install the sendmail-cf RPM. It should work then.

Do a "service sendmail reload" after changing sendmail.cf of course.

Paul.