Is there any way to track whether an email has been opened?

Question

I'm beginning to work on mailing-list software we use internally (EDIT: though we send emails externally as well, so we can't enforce policy on mail clients). Is there any way to track whether, when I send an email to a particular user, that email has been opened as opposed to being marked as junk or being deleted without being opened?

The simplest approach that I thought of was to serve a one-pixel custom image that would need to be loaded from our servers, but a number of mail clients block this approach. Is there an alternate approach that gets better data?

Answer 1

Mail clients block pretty much all of these kinds of attempts. The best idea is to give them an image that they would want to see if they read the message, and therefore they choose to display images in their mail client.