You can manage spam in one of two ways - sign up for a server-based service, such as Eircom's Email Protector, or use a local solution. A server-based solution screens all e-mail as it passes through a computer known as a mail server and checks the email's content and/or point of origin and thereby decides whether it is spam or not. If it is deemed to be spam it is not forwarded on to your inbox and will never arrive on your PC. These services are rarely 100 percent effective and we have found with Eircom's service, for which there is a monthly charge, that it eliminates approximately 70% of the spam destined for our Eircom e-mail account.
To deal with the remainder that slips through the server-based solution will require a local solution installed on your PC. There are a wide variety available, both commercial and freeware, and a quick google of "spam solutions" will provide you with a number of options.
Here at PC Medic our way of dealing with spam is to use Thunderbird, available for free from http://www.mozilla.org/ , as our e-mail client. Thunderbird has a built-in spam filter which, after a week or so of training, achieves almost a 100% hit on spam. It is simple to install, will import all your existing Outlook Express folders and mail settings, and does a great job of managing the spam that does get through. Check it out. For more on spam check out this link.