Re: open proxy

[Mel <rockchick () totalise co uk>]

I'm not familiar with Domino so configuration may be different, but when 
you set up your mail server, were you not prompted to enter details about 
relay hosts and relay targets? - ie. specifying which IP address(es) the 
mail server should receive mail from (usually ONLY your firewall) and which 
IP addresses it can send mail to (this can be any, or you can specify 
domains to which email should not be sent).

Blocking open ports will not necessarily stop your mail server being an 
open relay.  Obviously the machine should be locked down anyway and have 
only port 25 open to decrease the chance of it being attacked, but you need 
to lock it down in its configuration.  At the moment it sounds like it's 
accepting and routing on mail from any IP address, and thereby probably 
being used by hundreds of spammers who will be spoofing their IP address 
using yours instead, and getting your organisation blacklisted.

Here are some links for you to check out:

http://www.ordb.org/
http://www.abuse.net/relay.html
http://mail-abuse.org/rbl/relay.html
http://www.openrelaycheck.com/


At 12:31 PM 3/30/2003 +0200, Joost Ernest wrote:
> Hello all,
>
> I have a question regarding to "open proxy". We are using Domino server
> as our mail server in a w2k server environment. A week ago we started to
> receive a-mail from a Dutch ISP dat our mailserver has been listed in an
> Open Proxy Database. As a result of this we can't send e-mail at all...
>
> I have started to block some ports explicitly (135, 139, 443, 1080,
> etc..) I also read some articles about this subject in which was written
> that i should use Authentication for every user that wants tos end
> E-mail. I know how to configure this in Exchange but i don't know how i
> can arrange this with Domino server.
> Any suggestions en url's would be appreciated!
>
> Thanks!
>
> Joost Ernest
> The Netherlands
>
>
>
>
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