All .COM / .NET domain names now exist

[Travis Roy]

>   This will have the immediate effect of making network trouble-shooting
> much more difficult.  Before, a mis-typed domain name in an email address,
> web browser, or other network configuration item would result in
> an obvious
> error message.  You might not have known what to do about it, but at least
> you knew something was wrong.  Now, though, you will have to guess.  Every
> time.

Well, while it's not a browser error message what Verisign spits out makes
it quite clear that the domain is not an owned/valid one:

We didn't find: "www.sadfjiasjddlksfjlaksdjflkas.com"
There is no Web site at this address.

>   Some have pointed out that this will make an important anti-spam check
> impossible.  A common anti-spam measure is to check and make sure
> the domain
> name of the sender really exists.  (While this is easy to force, every
> little bit helps.)  Since all .COM and .NET domain names now exist, that
> anti-spam check is useless.

Can't you just check for a valid MX record? I know that's what most ISPs are
doing now.

"host -t MX scootz.net" Returns:
scootz.net mail is handled by 0 mail.scootz.net.

"host -t MX sadfjiasjddlksfjlaksdjflkas.com" Returns nothing