Regarding Blocking access

[Manish Kathuria]

On 3/13/07, siva kumar <sivasunil1000 at yahoo.com> wrote:
> Hi,
>
> Thanks for replying,
>
> yes, i am using this linux server as gateway server for lan.
> We aren't having any SMTP server.
>
> Can you please tell me how can i check the open relays. and how can i block
> those relays.
>
> Please help me
>
> Thanks & Regards
> Siva Kumar
>

Since this linux system is acting as a gateway for your LAN, you can
start by making a firewall on this system using iptables. Allow only
selective outgoing traffic as per your requirement. Your problem might
be because of some worm infected system inside the LAN. You can also
make sure that no MTA (sendmail / postfix / exim) is running on the
gateway or listening on the external interface.

-- 
Manish Kathuria
Tux Technologies
http://www.tuxtechnologies.co.in/