The release notes state: By default, sendmail does not accept network
connections from any host other than the local computer.

To fix this problem:
Edit the file: /etc/mail/sendmail.mc

Change the local address defined in the DAEMON_OPTIONS line(127.0.0.1)to
0.0.0.0
so that it accepts from all IPs.

You will then need to regenerate /etc/sendmail.cf by running:

m4 /etc/mail/sendmail.mc > /etc/sendmail.cf

-- 
Mark Hutchings
desynergy@onebox.com - email

---- Jonathan Hutchins <hutchins@opus1.com> wrote:
> Can't get sendmail to accept connections.  RH7.3, all current patches.
> 
> It's not sendmail: removed, reinstalled.  RH has a default DAEMON_OPTIONS
> lines that's supposed to prevent connections except from localhost.
>  Turned
> this off.  Verified on another host that turning this on and off indeed
> disables/enables connections other than localhost.  With it on, netstat-a
> shows the address localhost for the smtp port, with it off it shows
> a star.
> 
> It's not hosts.allow/hosts.deny.  I can get it to generate "tcpwrappers:
> connection refused" entries in the log by blocking sendmail in these
> files,
> but with _everything_ unblocked connections are still refused.
> 
> It's not firewall rules.  The system is behind a firewall, and if I
> try
> "iptables -L" I get messages about the modules not being loaded.  I
> conclude
> that there is no default firewall on the affected system.
> 
> I'm at a loss.  Any suggestions?
> 
> 
>