Getting email opening notification with mail()?

[Cunegonde]

This may be a silly question due to my limited knowledge of MIME but I don't see anything about getting a notification of email opening after having sent out mass emails with the mail() function. Is this possible?
Thanks,
C.

[matt_4013]

Add in a header like this:

$header  = "From: Frank <[e-mail]>\r\n";
$header .= "Reply-To: John <[e-mail]>\r\n";
$header .= "X-Confirm-Reading-To: Frank <[e-mail]>\r\n\r\n";

mail($recipient, $subject, $body, $headers);

[superwormy]

Note that the mail() function is not actually doing anything in this case, mail() is just for sending mail.

Another option ( if you are sending HTML email ) is to embed an image in the email... something like:

<img src="http://www.MyDomain.com/MyScript.php?email=[e-mail]" />

Then, make that PHP script record each access to that 'image' ( make it is an image by fpassthru() or readfile() and image, and make sure you send the correct Content-type header() ), and then you can pretty much assume, anyone who saw the image will have seen the rest of your eamil too :-)