plugin for emails to prevent spam but also let mailto working?

Question

Spam prevention should be done on the email’s servers side, by that I mean you should not disrupt your usability because of spam, instead you should use a proper spam block or filtering service on your email side. For example I have been using Postini for years and have pretty much no spam to contend with.

Another option to prevent really badly written bots is a simple encoded email using ascii or JavaScript, that way the bot reads the source and it is useless but the user is still presented with a valid clickable link,

for example:

    **[email protected]**
    //becomes in ASCII

 <a href="mailto:&#116;&#101;&#115;&#116;&#064;&#101;&#120;&#097;&#109;
 &#112;&#108;&#101;&#046;&#099;&#111;&#109&#116;&#101;&#115;&#116;&#064;&#101;
 &#120;&#097;&#109;&#112;&#108;&#101;&#046;&#099;&#111;&#109;"></a>

   //
   //or a javascript example:

<SCRIPT LANGUAGE="javascript">



    var first="ma";
    var second = 'il';
    var third = 'to:';
    var address="test";
    var domain = 'example';
    var ext="com"; 
    document.write('<a href="');
    document.write(first+second+third);
    document.write(address);
    document.write('@');
    document.write(domain);
    document.write('.');
    document.write(ext);  
    document.write('">'); 
    document.write('Click Here to Email Me!</a>');

</script>

You can find a generator here , http://www.ohlone.edu/org/webcenter/emailencoder.html
or here http://www.wbwip.com/wbw/emailencoder.html and there are some javascript ones out there as well like this jQuery one http://plugins.jquery.com/plugin-tags/email-encode