On 5/11/2013 7:34 AM, Pol Hallen wrote: >> And the most effective countermeasure to spam originating from devices >> on the LAN has nothing to do with Postfix. As most spamware in the wild >> today still attempts to send direct-to-MX, simply creating a TCP 25 >> egress filter at your edge router/firewall will give the best bang for >> the buck. This simply means creating a rule to drop all outbound TCP 25 >> connections except those originating from the IP of your Postfix MTA. > > I don't understand. > > Situation: A real user using browser connect to squirrelmail and send a > mail. It's ok. > > But if this user create a mail bomb using squirrelmail how way to spam I > can have this problem. > > If a drop port 25, user can send any mail. > > Or tell me what I don't understand.
It would probably be best at this point for you to describe your network, your mail usage scenario, so we can give you targeted responses. I.e. is this a 1. typical office environment mail server 2. SOHO or personal server 3. university mail server 4. ISP mail server -- Stan
