SPAM from own customers

Brian Bruns bruns at 2mbit.com
Tue Dec 2 19:32:16 UTC 2003


----- Original Message ----- 
From: "Suresh Ramasubramanian" <suresh at outblaze.com>
To: "Michel Renfer" <michel.renfer at lan.ch>
Cc: <nanog at merit.edu>
Sent: Tuesday, December 02, 2003 2:23 PM
Subject: Re: SPAM from own customers

>
> Virus filtering
>
> Rate limit (+ script to auto terminate user) and smtp auth on outbounds
>

SMTP AUTH is becoming risky if its not carefully setup and monitored.  I can
name one big time spammer who has warmed up to cracking weak passwords on
e-mail systems that do SMTP AUTH.  Means you'd have to filter your outbound
mail servers port 25 from anyone not inside your network or a trusted
source.

Virus filtering is a must, but, alas, not all mail servers filter *outgoing*
mail.  Most filter only incoming mail.


--------------------------
Brian Bruns
The Summit Open Source Development Group
Open Solutions For A Closed World / Anti-Spam Resources
http://www.sosdg.org

The AHBL - http://www.ahbl.org




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