1. Tom wants to send email to Dick.
   
2. Dick's email is hosted by a popular ISP the name of which is often misspelled.
   
3. Tom misspells the domain part of Dick's address, composes an email and hits "send".

Now what happens?

Does Tom immediately see a bounce back from his mail router - "no route found to exapmle.com - check spelling and try again"?

Well ordinarily he would but not this time. Why?

Because Harry (2) has thought of a way to make a buck. Harry has worked out a large number of common misspellings of popular domain names and has registered them all. He is hosting a web page on www. for all of them and this web page sort of looks like a search engine (3), but also proclaims "this domain may be for sale" (yes - may be for sale - get off the fence Harry).

But Harry has not stopped there. He has also set up a wildcard A record for all of these domains so that not just www., but also the domains themselves as well as all subdomains return that same pseudo search/for sale page when hit with a browser (3 again).

Now, can anyone see the mail routing problem here? That's right. Harry's web server isn't listening on port 25 - why would it (4)? But Tom's mail router can see that A record for exapmle.com and is trying to connect to it. Because it is failing to connect, it simply backs off and retries periodically for 24 hours. Then Tom's mail bounces, but not with a useful message that might give him a clue about why his mail bounced, just with a generic time-out message. Tom assumes a transient problem at Dick's ISP and hits "resend". Now lather, rinse and repeat.

Consequence - an extended delay in communication from Tom to Dick (and no revenue for Harry either - let's face it, who other than Harry himself really wants to buy exapmle.com?).

Yes, Tom should be more careful when addressing his email, but Harry's behaviour is unthinking and selfish (and unlikely to be significantly remunerative).

1. For non-British readers, ASBO is shorthand for anti-social behaviour order, a British legal instrument used to censure people who behave in an antisocial manner (e.g. by keeping neighbours awake with loud music in the small hours).
   
   
2. Harry will be the first recipient of the Internet ASBO, when it is invented, though we may have a long wait.
   
   
3. Remind anyone of SiteFinder?
   
   
4. Because Harry, if you listen on port 25 and send "5xx this domain isn't the one you wanted but IS for sale - http://www.exapmle.com" when mail servers connect, then many extra pairs of eyeballs will be exposed to your little scam business opportunity. You see. Dumb as well as greedy.

Category: T'Internet
Technorati: T'Internet

1. Chris Linfoot13/05/2009 20:05:02

Three off-topc comments removed (including one pointing out the off-topicness of the other two, for which I am grateful).

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