Is there a way to determine whether an e-mail reaches its destination?

Question

I have a PHP script that sends out critical e-mails that needs to reach its destination. I know how to check whether the e-mail sent successfully, the only issue is knowing

Answer 1

All the tracking links and webbugs assume that people actually open the email and enable remote images, or click links. Which is all flawed.

To make sure if an email is received and not returned, I'd do the following:

1. Add Errors-To header (set to e.g. bounce@domain.com)
2. Add Return-Path header (set to e.g. bounce@domain.com)
3. Pick up the email box (bounce@domain.com) and parse the emails

This lets you check when an email came back, based on the message content you can probably figure out which one bounced/came back.