Email is read? How to determine

[Habtom]

Quite a few months back, I tried to determine if an email sent to a customer is read or not by attaching images to it, and if the image is called then you know the customer has read it or something similar. Images are being blocked in many now.

Using PHP, how would you know if a customer has read your messages or not?

Habtom

[lorax]

Do you mean to include the PHP in the email - which wouldn't work?

[Morgenhund]

Include multiple "marked" links into e-mail, like:

New products: www.#*$!.tld/newsletters.php?id=121212&dest=products
Testimonials: www.#*$!.tld/newsletters.php?id=121212&dest=testimon

Then watch for $_GET['id'] in newsletters.php, save stats into DB and redirect to a corresponding file.

This is the only reliable way, this does not show an exact number of users who has read it, but at least who has acted in some way. You might use this information together with pictures-"bugs" (where not blocked) to get an approximate number.