Email Obfuscators
A recent study concluded that 97% of spam is the direct result of posting email addresses to Web pages. Harvesting email addresses from websites is a major way the spammers get them. They use specialised search robots that filter email addresses out of the pages automatically and add them to the address databases used by the spammers. Once in a database, addresses are often sold to other spammers and added to more databases.
There are measures to reduce the spam in your mailbox:
Don't give your private or office email address away on websites when signing on for a free service.
When signing in or filling order forms on the web check for "smallprint" options that say you are willing to receive advertising emails by the company you are dealing with and/or 3rd party. Deny it.
Never use the "option" to sign-out of a spam mailing you received. Your reply will only confirm to the spammer that your email address is active and he often will sell it as "confirmed" and "opted-in" address.
Use spam filters on the mail server, if you can.
Use spam filters in your email client.
Do not publish your email address in a way robots can easily harvest.
There are several ways that can be used to avoid harvesting.
Using the robots.txt File
The robots.txt file specifies where a spider can go or not go within a site.s structure. Therefor it is recommended to disallow visiting certain directories and pages that contains e-mail addresses. It doesn.t necessarily means that they will respect such rules.
A similar thing can be achieved by using the meta header tags but again no one can guarantee that they are indeed respected by everyone.
By using forms the e-mail address isn.t showed at all on the page. The user fills out a form, clicks submit, and hopes it gets to somebody. Still many users don't trust filling out a form and will withhold feedback
Displaying images on the site instead of clickable links seems to be a safe enough modality to hide the address but it is quite a tiring job to make them all in Photoshop and then re-do them if the site changes layout. This can be done automatically by the code though while still being not clickable.
For those who don.t respect the robots directives the webmasters have developed various techniques for combating theft of email addresses. JavaScript can be used, splitting the address and holding it in several variables only to write them out together on the page in hope that the often simple retrieving mechanism doesn.t figure it all out. It is also necessary for the visitor to have JavaScript enabled. Or not, if the enconding is done locally and the obfuscated address just pasted in the page where needed. Do not use just any on-line e-mail obfuscator to do that, not all of them can be trusted not to steal your address and sell it to spammers in the process.
The
address can be obfuscated using a combination of Hexadecimal and/or ISO
characters in place of the letters which make up an email address. It
makes a
big array of those codes. The visitors using a Javascript enabled browser
will
see the address and be able to send mail via a standard
mailto:
link, however any e-mail harvesting agents will merely see an array of
numbers, not even an @ sign will be visible. Those without a Javascript
enabled browser should find the email, suitably camoflauged, in the
noscipt
tag or it needs to be
obfuscated
using a simpler
method.
More complicated JavaScript obfuscators perform several non-trivial computational tasks to encode addresses, not a simple replacement of each character by its entity code or a string concatenation, as done by most anti-spam encoders. JavaScript is the standard computer programming language for use on web pages. To be able to perform the computation prescribed by the code, a software application must be able to understand that language. All recent web browsers do. This is however not the case of webcrawlers.
The javascript versions will only work if the viewer of the page has javascript turned on. Most people do. The non-javascript versions still provide effective protection today but are more likely to become ineffective as spammers adapt to the technique. Javascript is likely to remain effective against harvesting for as far in the future as it can be predicted today.
The email address is encoded within the source code of the website. Whenever a visitor clicks the link, a javascript function will decode the encoded text. At the moment, most spambots only interprete the source code of websites and do not execute javascript functions. A spambot cannot know which javascript-function will reveal an email address. This is the reason why the names of the javascript-functions do not include the words .email.. Each hint given to a spambot is a hint too many.
The best way to do this is dependent on the type of website. For static pages, one can use an online generator to generate the encoded source code. In case of a dynamic website, it depends on the scripting language used. Some email obsufcators also come with a dynamic implementation. The dynamic way of working is more flexible when something needs to be changed and it keeps the source code more readable than the static solution.
To take it even further and fight the battle with the same weapons one page containing contrived junk mailto addresses can be dropped in the root directory with a link provided to it and adjusted in such way to trap e-mail harvester in an infinite loop.
Online Obfuscators:
Download Obfuscators: