Here is a list of things you can do to help prevent receiving spam in the first place:
Do not use a catchall email account on your domain(s). Only list aliases and POP accounts that you actually use. This stops the frequent spams that fire off emails to a list of names on a domain.
Obfuscate your email addresses on your website, i.e. replace them with JavaScript "trick" email addresses, or, switch to web forms for initial contact, rather than displaying an email address.
Never, Ever, click on any links in any spam email- especially not to "unsubscribe".
All this does is confirm to the spammer that they have a "live" address.