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How to hinder the Spammers

I hate junk email (or spam) and all those involed in its creation. It wastes bandwidth and time. It is inevitable that you will have to put up with some spam, but their are things you can do to minimise your exposure.

Spammers get hold of your address in a number ways :

  1. They buy lists of email addresses from others.
  2. They collect email addresses from web forms. eg download sites which require you to enter an email address or register in some way.
  3. Web Scanners. These are programmes which scan thousands of web pages a day looking for email addresses.
  4. Mail Server 'Bombing'. This is when a spammer will try and email a load of common names eg fred@yourhost.com, john@yourhost.com and see which work.

Have a look at http://www.private.org.il/harvest.html for a more thorough discussion on how spammers harvest email addresses.


What can you do to stop spam ?

  1. Get a 'throw away' email address from somewhere like yahoo, you can use this address for bulletin board postings, download registrations etc. Yahoo is particularly good, because it now has a 'bulk mail filter'. If you find your throw away address is getting too much spam, just get another one.
  2. Do not publish your email address directly on your website. Web Scanners will pick it up and you'll end up receiving junk. Some alternative techniques for publishing email addresses are discussed below.
  3. If spam does get through, use SpamCop to report the spammers and (hopefully) get them shut down.

I need to publish my email address on my website ? How can I avoid getting spammed

Most Web Scanners are compratively simple programmes and they can be confused if you publish your address in a non standard way on your site. A few examples are shown below :

  1. Instead of writing 'fred@myhost.com' put 'fred at myhost.com'. Most people will understand this, but the scanner will most likely ignore it because of the missing @ character.
  2. Put the email address into a graphic (see below). Web Scanners are unlikely to be able to parse graphics. (Note : This will probably break accessibility guidelines)
  3. Embed the email address into a Javascript script, on multiple lines. eg put this into your main web page :

    <script language="JavaScript" src="email.js"></script>

    Now create a seperate file called 'email.js' in the same directory, containing something like the following :

    document.write("fred");
document.write("@");
document.writeln("myhost.com");

    If the web scanner is unable to execute and interpret the output of the javascript file, the address will be ignored (I have a strong suspicion that some web scanners are using javascript interpreters to defeat this technique). However, to someone viewing the page with a normal web browser, the address will appear to be unaltered. This technique is used on my contact page.
  4. If you're feeling really nasty, you could add the WPoison script to your website. This script attempts to mess up web scanners by deliberatly feeding them false information and locking them up. This is installed on my site via a nearly invisible link in the far top right of my main home page. Or click here to view the output of this script.
 

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Page last modified : 13 October 2005