How to check if the mail has been sent successfully

I am developing an Asp.Net application, where I am sending a mail to the user's email address, if he forgets the password.

I want to check if the mail has been sent sucessfully or not. Is there any method 开发者_如何学Goto know that for sure.

EDIT

In case if an email id does'nt exists, then would I detect a failure.

---

if your SmtpMail.Send(message) method returns no error, it means the email was sent to the SMTP server, then you are out of your jurisdiction, that is how far you can know.

---

Put the .Send(msg) method in a try catch block, and catch SmtpFailedRecipientException.

try
{
    mail.Send(msg);
}
catch (SmtpFailedRecipientException ex)
{
    // ex.FailedRecipient and ex.GetBaseException() should give you enough info.
}

---

If you're using System.Net.Mail try out

message.DeliveryNotificationOptions = System.Net.Mail.DeliveryNotificationOptions.OnSuccess;

---

According to spec:

S: 220 smtp.example.com ESMTP Postfix
C: HELO relay.example.org
S: 250 Hello relay.example.org, I am glad to meet you
C: MAIL FROM:<bob@example.org>
S: 250 Ok
C: RCPT TO:<alice@example.com>
S: 250 Ok
C: RCPT TO:<theboss@example.com>
S: 250 Ok
C: DATA
S: 354 End data with <CR><LF>.<CR><LF>
C: From: "Bob Example" <bob@example.org>
C: To: Alice Example <alice@example.com>
C: Cc: theboss@example.com
C: Date: Tue, 15 Jan 2008 16:02:43 -0500
C: Subject: Test message
C:
C: Hello Alice.
C: This is a test message with 5 header fields and 4 lines in the message body.
C: Your friend,
C: Bob
C: .
S: 250 Ok: queued as 12345
C: QUIT
S: 221 Bye
{The server closes the connection}

As soon as server says 250 Ok: queued as 12345, you cannot know for sure if it had really sent an email or not, or whether it was delivered.

---

You can use the DeliveryNotificationOptions to receive a receipt.

If you have a MailMessage object named mail, do this:

mail.DeliveryNotificationOptions = DeliveryNotificationOptions.OnSuccess;

---

No. E-mail (SMPT based) is an unreliable transport protocol and although there are some hacks to detect that an e-mail has been received and read, e.g. by embedding an individualized image URL in the e-mail and tracking that the image has been requested by the recipient's client, there is no absolutely reliable way to fulfil your request.

---

The SmtpClient.Send method will raise an Exception if there's a problem sending. But beyond getting that message to the SMTP server, there's no way to know if it makes it to the destination from there.

---

I'am using gmail SMTP for sending mails with my program. A fake mail sent returns Ok even with SmtpFailedRecipientException trap.

But when I check with outlook my gmail recipient I see that mail was not sent with explanation. With a subject Delivery Status Notification (Failure)

My question is it possible to get this notificiation whitin the program.

I found this but it's not for POP

Notify C# Client, when SMTP Server receive a new Email