Is there a recommended way to check if a mail is read by its recipient?

Question

Is there a recommended way to check if an email sent by an application was read by its recipient?

One way is to send an image in the html with some querystring parameters and handle that request, but the problem with this approach is that most of mail clients block images.

Can I do the same with stylesheets? or do stylesheets also get blocked by mail clients?

Is there any other way?

Thanks in advance.

Answer 1

Is there any other way?

You can use read receipts, but (like embedded images) they can easily be turned off. So essentially, the answer is... you can't, reliably.

Answer 2

For security purpose all external content would be rendered optional on most of the mail client.

So to know if someone read a mail

• either he displays the picture, js, CSS, anything included in your HTML.
• he clicks on a link to your website which would have been prepared with an unique identifier