how check a validated Email Exist Or Not Without Sending test Email by c# codes?

how can we check that a validated Email exi开发者_运维问答st Or Not Without Sending test Email by c# codes?

we can check Validation of that email by many ways...

but what about existence?

is it possible to do that or not ?

thanks in advance

You should look at these websites. I've used a similar method to these three in the past when validating users emails for a federal website that required an authentic email address.

http://tools.email-checker.com/

http://verify-email.org/

http://www.technixupdate.com/check-whether-an-email-id-is-valid-or-not/

A mail server will usually quickly send back a response telling you if the email is valid or not, that is what you're going to be looking for.

As well, SO already has a few posts on this: Checking if an email address exists

is one of them.

Update:

I love the existence tag...!

You could possibly use C# to run a cmd command - telnet. Then output the results to a text file and read them into to your C# app. This should help - http://www.webdigi.co.uk/blog/2009/how-to-check-if-an-email-address-exists-without-sending-an-email You will need to know the details for the mail server names though. You might be able to do this directly from C# but I have only done it through telnet.

I don't know if there's a good way to do what you're looking for, but a solution that might get you part of the way there is to ping the domain to at least make sure that exists.

Here's an MSDN link which explains how to ping from .NET:

http://msdn.microsoft.com/en-us/library/system.net.networkinformation.ping.aspx

You can use a Regex Validation on the form before the user submits the data. It's an inbuilt tool in Microsoft Visual Studio where you can pretty much drag and drop :) You should be able to find it in the validation section . Regular expression Validator