PHP: Check who had read sent email?

Question

I am sending email to some users and wants to know who had read it, means if some one had read that email then a log file will maintain which contain the email address of th

Answer 1

Add Header to email:

Disposition-Notification-To: you@yourdomain.com

As mentioned above it's not reliable and it's better to do something like this:

And log it in a database, although again this is restricted by the email client's ability to show images and sometimes it may even put the mail into junk because it doesn't detect an image... a workaround that would be to actually outputting an image (say your logo) at the end of that script.

Edit: A quick lookup at the phpmailer class gave me the following:

$mail->ConfirmReadingTo = 'yourown@emailaddress.com';

but it's the same as the Disposition-Notification-To method above.