Re: Stopping open proxies and open relays

["Rubens Kuhl Jr." <rubens () email com>]

Force all SMTP outbound connections from users thru a SMTP proxy. On that
proxy, force users to do SMTP Authentication; I've heard only once of a spam
code that will use the user's configuration info or dispatch e-mail thru
them. Even if they do, you can rate-limit messages/hour, unique mail
to/hour, disable mail service after a threshold, whatever sounds a good
policy to you.




Rubens

----- Original Message ----- 
From: "Adi Linden" <adil () adis on ca>
To: <nanog () merit edu>
Sent: Saturday, February 07, 2004 2:43 AM
Subject: Stopping open proxies and open relays


> I am looking for ideas to stop the spam created by compromised Windows
> PC's. This is not about the various worms and viruses replicating but
> these boxes acting as open relays or open proxies.
>
> There are valid reasons not to run antivirus software, coupled with
> clueless users, this results in machines that SPAM again just a few hours
> after having been cleaned.
>
> Adi