Email spam is really a global problem. Now, a question you need to ask yourself is, "Am I looking for a solution to incoming or outgoing spam?"
If you're looking for an "incoming mail spam fix" then probably SpamAssassin and Box Trapper are a starting point for you. I know SpamAssassin is available in the cPanel under the "Mail" icon. As preventative measures there are Exim tweaks you can make to prevent SPAM before it happens.
- RBL/SBL implementation in your Exim.conf.
- Dictionary Attack detection via your Exim.conf.
These are just examples of preventative measures that will work BEFORE SpamAssassin even starts working its magical powers.
If you're looking for an "outgoing mail spam fix" then this is strictly your admins work. I mean, your admin could look into many things to help:
- Disabling user nobody from sending mail.
- Enabling PHPSuExec.
- Checking your Mail Stats via the WHM for your server.
- Limiting the amounts of mail per hour under "Tweak Settings" in your WHM.
- Adding X-Headers via the "Exim Configuration" section of the WHM.
There are really alot of things you can do to help TRACK spam, but usually, if spam occurs, it occurs. You just end up dealing with the bloody mess afterwards.
SPAM is more of a forensics thing and less of a "I'm immune to it" thing. I mean, if a PHP script isn't coded well, it could potentially mean lots of SPAM outbound from your server, then again, if you've installed the tools above, you can definately track it down.
Hope this info helps!