Win the SPAM Arms Race – A Checklist Aside

Most seasoned net designer/builders have realized that posting an e-mail tackle on an internet site is a sure-fire strategy to assure a steaming pile of spam delivered to that tackle for years to come back.

Article Continues Under

Certainly, posting a unadorned e-mail hyperlink wherever on the internet (or in a newsgroup, in a chatroom, on a weblog feedback web page …) is usually the kiss of loss of life to your once-healthy tackle.


It begins innocently sufficient: the neophyte net developer codes his tackle right into a contemporary, new net web page to solicit the suggestions of his adoring followers.  “Electronic mail me!”  it beckons.  A short while passes. Then the barrage of e-mail begins.

Topic: Make 80k working from residence ...

The primary few spam emails appear entertaining.  Then irritating.  Following the so-called “unsubscribe” hyperlinks in every mail solely leads to extra mail. Finally, the duty of separating legitimate e-mail from junk turns into so time consuming and problematic that the developer is pressured to desert the e-mail tackle completely.

I do know this as a result of the developer was me –  and to this present day, years later, that e-mail tackle nonetheless receives dozens of undesirable e-mail messages each day.

Have you ever ever puzzled how, nearly immediately, your e-mail tackle is found, recorded, handed down, and handed round?  This occurs on account of hordes of Electronic mail Harvesting Robots (aka spambots).  These autonomous bots spider the online day and evening in waves, crawling pages and following hyperlinks till they uncover an unsuspecting MAILTO tag.  Then they pounce, devouring the tackle and sending it deep into the bowels of the online the place the ugly, festering spam corporations dwell.


Having realized your lesson, unwilling to submit your bare tackle on a web page once more, you try and buck the system, eradicating any risk that the spambots will detect your tackle.  As an alternative of offering an precise hyperlink, you sort:

you at instance dot com

Whereas this may idiot ’most all spambots, it fails completely at offering your viewers with an precise, clickable, e-mail hyperlink. Your viewers must learn and bear in mind the textual content after which sort it manually into their e-mail program.  Not an enormous deal, however this is likely to be the additional step that stops them from making contact with you.

Your purpose is to make their life simpler, not tougher; to encourage, not discourage, contact. So that you abandon this method and transfer on to one thing higher. However what?


Your subsequent transfer is likely to be to embed the MAILTO hyperlink inside a block of JavaScript, like this:

<script sort="textual content/javascript">
doc.write("e-mail me");

At first, this might seem like an acceptable resolution.  Not like net browsers which can execute the JavaScript and show your hyperlink appropriately, spambots ought to, in idea, ignore the JavaScript and due to this fact the hyperlink to your e-mail tackle.

Sadly, spambots can learn your tackle with out executing any code in any respect.  It is because the hyperlink exists as plain-text inside the parseable textual content of the web page, ripe for the selecting.

Drew McLellan was blissful sufficient to show this to us all together with his Encoded e-mail tackle harvester, a pleasant gadget that harmlessly scans your net web page searching for susceptible addresses. Run it in opposition to your present net pages and see what it finds. The outcomes ought to show attention-grabbing.


One of the best resolution builds on the JavaScript-wrapping thought, however quite than go away the bare e-mail tackle uncovered inside the easily-parsed JavaScript, the tackle is encoded –  translated –  into every character’s Numerical Equal, and then wrapped.

You see, each character may be mapped to its personal particular code which, when seen by an online browser, is translated again into that character.  The next desk provides you an thought of how this works:

char  code
a  a
b  b
c  c
1  1
2  2
3  3

Utilizing this method, you’ll be able to generate a whole hyperlink that can be rendered appropriately by the online browser.  Wrapping these codes but once more inside a JavaScript will additional restrict the possibilities your e-mail tackle can be assimilated.

NO ONE IS SAFE#section6

Sadly, no e-mail tackle printed on-line is completely protected from robots that harvest addresses, however changing your e-mail tackle to numerical equivalents after which wrapping the end in JavaScript ought to foil all however the smartest and most devoted spambots.


Changing your e-mail tackle into an encoded and JavaScript-wrapped hyperlink is a tedious course of.  Happily, nearly each programming language options a simple strategy to invoke this transformation.

This writer’s Computerized Labs Electronic mail Tackle Encoder, for instance, is a web-based useful resource that can deal with this course of for you.  Simply enter your e-mail tackle and the hyperlink data, and it’ll do the remainder.  You might also obtain a stand-alone program to run by yourself pc.  Each variations create the identical outcomes, and even let you specify cross-browser XHTML or HTML 4.01 code that validates.

On this code web page, you’ll discover a easy PHP operate that can deal with this transformation.Get pleasure from! {The product has been up to date since this text was printed in ALA problem 145. To obtain the most recent model, see the Computerized Labs merchandise web page. – Ed.}

Leave a Comment