Re: Validating email addresses

["David Gibbs" <dgibbs@xxxxxxx>]

<rob@dekko.com> wrote in message
OFE0CDEB20.253965C0-ON05256BA6.00733765@dekko-1">news:OFE0CDEB20.253965C0-ON05256BA6.00733765@dekko-1...
>  These people will have two addresses - a dekko.com
> address and a mountaincable.com address.  Still a ping to
> mountaincable.com should work, to my best guess.

Might, might not.  No specific corelation betwee the root domain name and
it's desginated mail receiver's ability to respond.

Perfect example: If John Ross's AS400 (the one that hosts midrange.com) were
to go dark (I know, it's an AS400, they never go down), you could still send
me email, as mail is being received by another system (just so happens to be
linux.midrange.com).  In fact, if linux.midrange.com were to go dark, and
John's AS400 stays up, there is might be *NO* way to send me email because
the MX system isn't receiving it (that's not the case, as I'm about to
explain).

Additinoally, in the current configuration, both midrange.com and
linux.midrange.com could go dark and you could STILL send me email, because
I have a backup MX that will receive and hold the mail.

Some backup MX's just hold the email for later delivery (mine delivers by
UUCP), but others are true mail system that a person would have to read
independantly.

> We are dealing primarily with businesses here.  How many businesses will
> have a ping fail with TCP3202, ( not TCP3210) yet still receive email at
> that domain?  I could be in for a rude shock but I'd like an example.

1. Anyone who outsources their email.
2. Anyone who has a backup MX

david