The first step in your antispam campaign may well be to understand spam and how it works.
Spam is usually defined as unsolicited e-mail that is delivered in bulk. It has become so prevalent because it's cheap, reaches the greatest number of folks in the least amount of time, and because it's unregulated. In the U.S. alone more than 50 million citizens are online, with their own Internet accounts.
For spammers this is an ideal situation. Even were it not to work, there's virtually no punishment other than subsequent inability to spam until a way is found around it. And ways are constantly found around just about everything we do in our antispam campaign. That's not to say you shouldn't try though.
Here are some of the things you can do:
First, don't respond - not even to say, "Hey you not nice person, get off my computer." First, it's a waste of time. As soon as the first batch of spam has been sent that spammer may very well have deleted that email address. It'll just bounce back. The second is that you're not talking to a live person anyway. And any response, no matter how negative, is noted by their system as a response. What this means to the spamming system is, "Hey this guy is interested. He answered our message. Let's send him the second message." If you have a provider that lets you note spam then do so. Block it if you want but that seldom really works. It's worth a shot, though, unless you're limited to the number of blocks you can place at which point you'll be forced to pick and choose.
If your provider allows spammers to get through what is going to happen eventually is that other sites will begin to block your provider if they do in fact police spam. Then you'll have trouble sending and receiving e-mail. That's when you step in and tell your provider that they start blocking spam or you're gone. There's nothing like an irate customer threatening cancellation to spur them into action. If they should not respond by blocking spam, then do follow through and change providers.
The primary principle for preventing spam is to avoid mailing to a list. We're all tempted to organize our emails into lists - business clients, friends, and so forth. Then we mail them all the same message. Saves time and effort. The problem here is not that you sent out one message but you didn't use the software necessary to hide each person's email from the others.
Not only does this set you up for spam but it's also just plain rude. It's like telling all those folks what your sister-in-law's address and phone number is without first asking her if it's okay to tell the buddy of your best friend's high school teacher where she lives. No, it's not. But where spam is concerned what happens is that a few of those folks are undoubtedly going to add everyone whose address they see to their own list, and send it on and on and on ad infinitum. It snowballs, and sooner or later there's a spammer who receives your name and your e-mail address.
Don't sign up with a site that offers you an antispam service. "Sign up with us, they say, and we'll add you to an antispam list." Wrong! They're spammers and you're now on their list.