Check if email address exists (not if email addrss is valid)

Hi,

Does anyone know if there is a serivce, a third-party
component or some
example code to check if an email address exists?

I do not mean to check if an email addrss is valid, I know
how to do that
using regular expressions. But even if an email address is
syntactically
valid, it need not exist.

Googling gives an overflow of irrelevant hits about users
that supplied a
non-existing email address...     :-(

(Cross-posted on DotNet-WinForms)

Thanks in advance,
Paul ten Brink
paul.ten.brinkphilips.com

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I've been on vacation so didn't see this one until now.  It
is such a
unique question that I had to respond.

If such a product existed, it would be heavily used by
spammers, and
therefore one should be glad there is no such thing.

To create one, one would need to be able to get into the
email database
of every server in existence -- something the server owners
would resist
with great vigor.  What you're looking for is virtually an
impossibility.

But in fact, there have been some applications written that
have
attempted to do something like this.  They're called
"worms" and
"viruses", and most of them propagate by
insinuting themselves onto
vulnerable machines and sending copies of themselves to
every email
address in a victim's address book.  If anyone of them had
also tried to
send the email addresses to a central location for storage
in a
database, then, by golly, THERE would be the thing you are
looking for.

Heh.

-----Original Message-----
From: Discussion of building .NET applications targeted for
the Web
[mailtoOTNET-WE
BDISCUSS.DEVELOP.COM] On Behalf Of Paul ten Brink
Sent: Monday, December 18, 2006 1:12 AM
To: DOTNET-WEBDISCUSS.DEVELOP.COM
Subject: [DOTNET-WEB] Check if email address exists (not if
email addrss
is valid)

Hi,

Does anyone know if there is a serivce, a third-party
component or some
example code to check if an email address exists?

I do not mean to check if an email addrss is valid, I know
how to do
that using regular expressions. But even if an email address
is
syntactically valid, it need not exist.

Googling gives an overflow of irrelevant hits about users
that supplied
a
non-existing email address...     :-(

(Cross-posted on DotNet-WinForms)

Thanks in advance,
Paul ten Brink
paul.ten.brinkphilips.com

===================================
This list is hosted by DevelopMentor(r)  http://www.develop.com

View archives and manage your subscription(s) at
http://discuss.develop.com


===================================
This list is hosted by DevelopMentorŪ  http://www.develop.com

View archives and manage your subscription(s) at http://discuss.develop.com