Mail Scanning on the Firewall?

zymurgist · 09-29-2003, 11:36 PM

I have a linux mail server running on my network behind a linux firewall. I'd like to have the firewall scan my mail for spam and viruses before the mail is forwarded on to my server. I've been using sendmail, but I'm a bit of a novice.

How do you suggest I set this up (or should I even bother)? Right now, I just port forward for SMTP traffice through my firewall to the correct machine.

darrenp · 09-30-2003, 06:27 AM

Give this a try:

http://www.eridani.co.uk/MailStripper/

Free trial available. It will sit on your firewall, accept incoming mail, filter it, and send it on to your mail server. Effectivly replacing the port forwarding of your firewall.

Looked at implementing it numerous times because it seems to be the best solution I've seen (and cheap!) but I'm too lazy and don't get that much spam yet!

zymurgist · 09-30-2003, 10:09 AM

That looks kind of cool, but I just need to be able to set up a sendmail client on the firewall that scans the mail and forwards it on to my mail server. I think I can get the scanning part down, but I'm not sure how to forward to another server.

darrenp · 09-30-2003, 10:51 AM

Thats exactly what this program does.

zymurgist · 09-30-2003, 11:51 AM

Okay, I'll take a closer look. Thanks.

leohuang · 09-30-2003, 12:36 PM

http://www.mailscanner.info/

It's a very powerful and nice tool.

chort · 09-30-2003, 01:01 PM

WARNING WILL ROBBINSON, DANGER!

Putting sendmail (or any MTA) on your firewall is a very BAD idea. MTAs in generally, and ESPECIALLY sendmail are the source of many security flaws and open the potential for your firewall to get exploited. It's generally a good idea to put this type of service (e-mail scanning) in your DMZ. If you insist on putting it on the firewall, use something that is very minimal and definitely do NOT use anything based on sendmail.