How to check whether email id exists?

[Maidenz08]

How do i check whether an email id exists or not?

I am following a three step validation process..

1) syntax validation- which is pretty straight forward

2) DNS validation - I'm able to do this too.

3) mailbox validation - I have read in many forums saying it is IMPOSSIBLE to check whether a particular email id exists. But take a look at this site.

http://www.dimplesoftwares.com/email...rlivedemo.aspx

When they can do it there has to be some way. I have searched every nook and corner but to no avail.. Any help would be greatly apppreciated.


Here's is wat im doing

 public void ValidateMailBox(string emailAddress)
        {
            string[] id = emailAddress.Split('@');
            string host = id[0];
 
 
            if (!CheckSmtpServerResponse(sock, SmtpServerResponse.CONNECT_SUCCESS))
            {
                sock.Close();
                bConnectStatus = false;
            }
            else
            {
                bConnectStatus = true;
            }
 
            SendData(string.Format("HELO {0}\r\n", Dns.GetHostName()));
            if (!CheckSmtpServerResponse(sock, SmtpServerResponse.GENERIC_SUCCESS))
            {
                sock.Close();
                bHelloStatus = false;
            }
            else
            {
                bHelloStatus = true;
            }
 
            SendData(string.Format("MAIL From: {0}\r\n", "[e-mail]")); //_SenderEmail));
            if (!CheckSmtpServerResponse(sock, SmtpServerResponse.GENERIC_SUCCESS))
            {
                sock.Close();
                bBlackListStatus = false;
            }
            else
            {
                bBlackListStatus = true;
            }
 
            SendData(string.Format("RCPT TO: {0}\r\n", "[e-mail]"));
            if (!CheckSmtpServerResponse(sock, SmtpServerResponse.GENERIC_SUCCESS))
            {
                sock.Close();
                bSendStatus = false;
            }
            else
            {
                bSendStatus = true;
            }
        }
 
        public void SendData(string message)
        {
            byte[] bytes = System.Text.Encoding.ASCII.GetBytes(message);
            sock.Send(bytes, 0, bytes.Length, SocketFlags.None);
        }
 
        public bool CheckSmtpServerResponse(Socket soc, SmtpServerResponse code)
        {
            string responseString;
            int responseCode;
            byte[] bytes = new byte[1024];
            while (sock.Available == 0)
            {
                System.Threading.Thread.Sleep(100);
            }
            sock.Receive(bytes, 0, sock.Available, SocketFlags.None);
            responseString = System.Text.Encoding.ASCII.GetString(bytes);
            responseCode = Convert.ToInt32(responseString.Substring(0, 3));
            if (responseCode != (int)code)
            {
                return false;
            }
            else
            {
                return true;
            }
            //return responseCode.Equals(Convert.ToInt32(code));
        }

[radcaesar]

The URL u specified send and receive some response from that mail-id and then it reports, Since it takes some time for the report. See that LOG.

[Plater]

SMTP has commands that can be used to verify a given mailbox, unfortunatly since it's not part of the minimal implementation, almost NO smtp server implement it (it can be used to generate directed spam).

What many places do, is send an email to the address, and that email gives directions on verifying that it exists. (Usually a special link with a unique id string to click or something)

[kunyunfang]

GOOD!
thank you!
I like the article!