Tracking Undelivered E-Mail using UTL_SMTP

Question

I am sending e-mail using UTL_SMTP. If there is any error in the e-mail delivery for e.g. say if the E-Mail bounced etc. then can i capture those events in my code?
E-Mail can bounce back for any reason. for e.g. e-mail address is not valid. What all error we can capture using UTL_SMTP?
Edited by: LostWorld on Jan 26, 2011 11:34 PM

Answer 1

LostWorld wrote:
I am sending e-mail using UTL_SMTP. If there is any error in the e-mail delivery for e.g. say if the E-Mail bounced etc. then can i capture those events in my code?Yes. But not via SMTP.
The SMTP server receives the mail. It tells the client (your code, mail reader, whatever) that is has accepted the connection. That is the extent of the conversation. The SMTP protocol does not report on delivery steps, delivery status and so on.
From a SMTP protocol perspective, the mail payload was delivered to that server. And that's it.
The mail delivery runs into a problem. It could be on the SMTP server that accepted your mail. It could be a SMTP server on the other side of the world that is passing your e-mail along, 24 hours later.
There are 2 types of problems. A soft bounce. This means that the server attempted delivery, and it failed - but the delivery attempt can be retried. For example, there could be a network problem (and this could shortly be rectified). In such a case, that SMTP server will look at the sender's address and send a soft bounce notification to the sender. It will describe the basic problem and how it will be handled - e.g. mail server may perform 3 more attempts at delivery in the next 12h and then hard bounce your e-mail.
A hard bounce is a fatal error. For example, the SMTP server attempts to deliver your e-mail to its final destination (the mail server of the recipient's domain). That server says that the recipient (mail user) does not exist at that domain.
In that case, the SMTP server will send the sender of that e-mail a hard bounce notification - informing the sender of what the fatal error is.
So in order to get the bounce message, you need to supply a valid sender e-mail address when delivering that e-mail to the SMTP server. You then need to monitor that e-mail account (using the POP3 or IMAP protocols) for bounce e-mail notifications.
However, even that will not indicate whether that original e-mail your code send was delivered successfully. And this is the bottom line - there are no guarantees. The SMTP and POP3/IMAP protocols cannot and do not guarantee you being able to determine whether or not an e-mail reached its intended destination.
This is often why e-mails are send with a URL and a request that the recipient please click the URL when receiving the e-mail. That is the only method to determine whether the recipient received the e-mail, provided the recipient is willing to click that URL in that e-mail message.