[CentOS] sendmail refusing incoming connections from outside

Hello.

I am scratching my head about sendmail for a simple thing:

I have a CentOS 4 box on which I would like to receive e-mails. when I type 'telnet localhost 25' I can connect successfully to the sendmail service. Now if I type: 'telnet 192.168.0.30 25' on the same host the connection is refused. It also refuses connections from another host.

I have edited the /etc/mail/access file and added: 192.168 OK But this doesn't help after a restart.

Does somebody know why the connection is refused ? I can see that behaviour on several CentOS box I have so it seems to be the new default. What parameter should I change to make it be accepted ?

Thank you, Daniel