I have a client who is acting very suspicious with nothing at all on his website (no pages or content), although he does have an email. I suspect he may be spamming but how can I know for sure?

Are there any scripts to prevent this? What should I do?

best is check log, it tell every think users does.

raw access logs?

If your running cpanel you can go to the exim/e-mail section in your WHM, and look at the e-mail stats page (forget the exact name). If you scroll down a little bit it will show you how many e-mails are going in and out for each user.

If your not running WHM, you can login via SSH and look through your /var/log/exim_mainlog and look for alot of outgoing messages from one user all relatively in the same time period.

You could also look at your mail-queu.

yeah check out going msges vis ssh, i belive what p[] mentioned works for all linux os'. becuase i run another control panel and it works fine.

Boy, I have about 9 domains with nothing on them, but have never sent a lick of spam. One has been blank for over 4 years.

So I would just cancel his account without warning, no need to look at any log files.

So you'd cancel the account of someone who may be a paying customer not doing anything wrong without finding out? Seems a bit quick. I'd get something more than a hunch (something in the logs), or check his bandwidth traffic. How much of it is via email?