How to Vaccinate
an Entire Site at Once
How Spam Vaccine Works
What Spam Vaccine does 
How it works What if my visitors don’t use JavaScript? What’s the trick? Any limitations? Will Spam Vaccine stop all spam?
- Why can’t the spammers decode Spam Vaccine?
What Spam Vaccine does
When human beings look at your page, they see a regular email address:
But when a spambot looks at your page, it sees garbage:
<script language="JavaScript"><!—spam_vaccine( new Array("info", "", "matterform", "", "com"), new Array(), "../nav/spam_vaccine/" );//—></script>
How it works
Spam Vaccine converts your email addresses to a complex JavaScript code. A browser like Explorer or Navigator converts the JavaScript into a human-readable email address. But the spambot isn’t smart enough to handle JavaScript, so all it gets is garbage.
What if my visitors don’t use JavaScript?
No problem. Spam Vaccine adds extra code to accomodate people who can’t or don’t use JavaScript. When a non-JavaScript browser looks at your page, they still see an email address:
info
matterform.com
But the spambot still sees garbage:
info<img width="11" height="12" align="absmiddle" border="0" src="../nav/spam_vaccine/at_medium.gif">matte rform.com
What’s the trick?
Spam Vaccine does three things to hide your email address:
- First it converts your email address to HTML entities. So “info”
comes out looking like info.
That alone can fool the really stupid spambots. But why stop there?
- Spam Vaccine then wraps this scrambled email address into a JavaScript
and juggles the pieces around. Spam Vaccine installs a JavaScript program
on your site to unscramble the address. Any modern browser program can
handle it without any problem. But a spambot is too stupid for that.
- Finally, Spam Vaccine adds extra code for visitors who can’t or won’t use JavaScript. But even this code will baffle the spambots because it doesn’t use an @ symbol. Instead, Spam Vaccine creates an image file that looks like an @ symbol. To a human, anyway. To a spambot, it just looks like unintelligible HTML code.
Spam Vaccine offers flexible preferences so you can choose exactly how your email addresses get scrambled.
Any limitations?
Spam Vaccine will vaccinate email addresses in plain text or inside hypertext links. To avoid breaking your pages, Spam Vaccine will not vaccinate addresses inside other tags, such as keyword tags or other JavaScripts. If Spam Vaccine finds an address on your site that it can’t vaccinate, it will warn you so you can take extra steps to protect your email address.
Will Spam Vaccine stop all spam?
Spam Vaccine will prevent spambots from getting your email address, but
there are other ways the spammers can find you. See our other anti-spam
tips for more ways to protect yourself.
Why can’t the spammers decode Spam Vaccine?
