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

It's impossible to just check if a mailbox exists without
sending an
email and receiving a response.
(Think of the implication for spammers.)


You have to create a send confirmation email with a link or
reply to
address that confirms the account.








-----Original Message-----
From: Discussion forum for developers using Windows Forms to
build apps
and controls [mailtoOTNET-WI
NFORMSDISCUSS.DEVELOP.COM] On Behalf Of
Paul ten Brink
Sent: 18-December-2006 09:14
To: DOTNET-WINFORMSDISCUSS.DEVELOP.COM
Subject: 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-Web)

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





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Not impossible - most mail systems you can check for this
without sending an
email by setting up the initial session using HELO and RCPT
TO.
At this point you will receive a mailbox unknown or no error
and can then
disconnect.



-----Original Message-----
From: Discussion forum for developers using Windows Forms to
build apps and
controls [mailtoOTNET-WI
NFORMSDISCUSS.DEVELOP.COM] On Behalf Of Adrian
Martin
Sent: Monday, December 18, 2006 1:58 AM
To: DOTNET-WINFORMSDISCUSS.DEVELOP.COM
Subject: Re: [DOTNET-WINFORMS] Check if email address exists
(not if email
addrss is valid)

It's impossible to just check if a mailbox exists without
sending an
email and receiving a response.
(Think of the implication for spammers.)


You have to create a send confirmation email with a link or
reply to
address that confirms the account.








-----Original Message-----
From: Discussion forum for developers using Windows Forms to
build apps
and controls [mailtoOTNET-WI
NFORMSDISCUSS.DEVELOP.COM] On Behalf Of
Paul ten Brink
Sent: 18-December-2006 09:14
To: DOTNET-WINFORMSDISCUSS.DEVELOP.COM
Subject: 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-Web)

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





  Opinions expressed in this email are those of the writer
and not the
company.  E-mail traffic is monitored within Johnston Press
and messages may
be viewed.  This e-mail and any files with it are solely for
the use of the
addressee(s).  If you are not the intended recipient, you
have received this
e-mail in error.  Please delete it or return it to the
sender or notify us
by email at postmasterjpress.co.uk