I currently have a Linux 8 RH server running sendmail. This server only takes mail from my firewall, scans it and then relays it directly off to my local mail server on the same local network.

This is ALL this machine does. How can I make sure sendmail and the server is safe from the spammers in this world who like to use it as their own relay??

ThAnkS

There are some good apps out there... spamcontrol is one that I use...

Basically you need to monitor your logs, and keep sendmail updated when security holes get filled.

You don't really have to worry about spammers if you aren't an open relay... there is a way to test your server by trying to make it relay mail to or from bogus domains.... google will help you there.

Read up on creating your sendmail.cf file.... there's alot going on there.

SSL and TLS are always good too...

HTH

If that's all your mail relay is doing, and if you're concerned about security, DITCH SENDMAIL. It's had a horrifying number of severe security flaws over the several decades of it's existence.

Qmail, Postfix, and Exim were all designed as sensible Sendmail replacements. Postfix is probably the most simple to setup and possibly the most secure of the replacements. There are several things you can do in Postfix to lock it down, including dropping dangerous MIME parts (or messages that contain dangerous MIME parts). Refer to the Postfix documentation and do some Googling for details.

Thanks for all the responses. I have heard sendmail does have many holes in it. I will start researching Postfix today..

ThAnKs

if im not mistaken its one of the top 5 ways a linux system gets compromised.