When you send an email, your Email Service Provider automatically adds special code that enables the tracking of certain responses. It’s possible to track

ESPs collect and aggregate the tracking data from your emails and generate a tracking report so you can see the tracking information in an easy-to-use format (see Figure 12.1).

Email tracking data can be a bit confusing because tracking requires a combination of technology and human interaction, and both have certain limitations. The following sections show you how tracking works so you can understand the limitations and gain a realistic perspective on what your tracking data actually means.

True delivery to the email inbox can be measured by a third-party service called Return Path. If you use an ESP who measures delivery through this service, you can trust that your email delivery rates will be about the same as the ESP’s delivery rate. If your delivery rate is higher or lower than the ESP’s average, it probably means the quality of your email list or email content is above or below average.

When you use an ESP to send your email, bounced email is returned to the ESP’s computer so the ESP is able to generate a report that a human can read. The report tells you why your emails bounced and displays them in categories so you can take action on the information in batches (see Figure 12.3).

The bounced email report let’s you see which emails bounced, why they bounced, and which emails were blocked. Some emails are returned to the sender with no code or nonstandard code. These bounced emails are usually placed in a category such as “other.”

If you don’t have any images in your email, your ESP puts a blank image in the email in order for open tracking to work. The image can’t be seen by the recipient, but it can still be enabled when recipients enable images to display in their inboxes.

Open rates have been trending down over the years, but not because fewer people are reading emails. It’s because fewer and fewer email programs are displaying the images in emails automatically. This means individual recipients are getting used to scanning and reading emails without enabling the images to display.

Many marketers use their click-through rate as a judge of whether the email was successful, because it indicates that people were interested in the email, and the email was able to drive traffic toward the place where the link points.

Forward tracking is a good way to determine whether your email content is valuable because people won’t forward your email to a friend or colleague unless the content is valuable enough.

Since the spam or junk buttons report complaints to the company that supplies the email program and not to the sender of the email, many ESPs have formed relationships with the companies who provide these buttons to their customers so they can report spam complaints back to their customers. These relationships are known as “feedback loops,” and they typically operate with a certain degree of anonymity. That means if your ESP has feedback loops, you probably won’t know who complained about your email, but you will know how many people complained.