As we all know, email delivery is challenging in and of itself. However, once an email leaves your application, server, or mail client, you quickly encounter another obstacle: understanding what actually happens to that message. There are several different metrics that the average company should consider tracking in order to gain useful insight and produce educated business decisions.

In this post, we will cover a subset of the statistics that SendGrid tracks for its users and explain what each means. The metrics featured here are mostly relevant to email marketing-focused messages. To learn more about bounce management, and how they’re handled at SendGrid, reference this article.


A request is an email sent and is reported in your SendGrid dashboard every time our servers get a “request” from your application or server to send an email to one of your customers.


“Delivered” seems pretty obvious, right? At a fundamental level, a delivery is recorded when a request to send an email results in an email being delivered to the end recipient. However, there is a little more to it. You could consider an email classified as “delivered” to mean that an ISP has accepted the email and said “OK, I’ll take this email off your hands.” However, “delivered” does not necessarily mean that your email is in the recipient’s inbox, and it could even mean that it was delivered to the spam box or completely dropped from their system after being accepted. Lastly, if an email is “delivered” you can be certain that it was not deferred by the ISP (“deferral” will be covered in Part 2 of this post).

Clicks & Unique Clicks

The “Clicks” statistic represents the total number of times your users have clicked on the various links within your emails. “Unique clicks” represents the number of unique individuals that have clicked the links in your emails. So, if a certain customer clicks the same link more than once, it will only be reported once in the “unique clicks” count.

Opens & Unique Opens

The concept explained above regarding clicks also applies to opens. An important thing to keep in mind when evaluating numbers around opens is that many email clients often do not load images by default. Therefore, a customer could potentially open your email, read it, and even click a link, without an open being reported. This is obviously not ideal, but as we advance in our tracking mechanisms, we should be able to gain greater accuracy in instances such as this.


In order to maintain compliance with CAN-SPAM laws, any email that is sent in bulk to a mass audience should include an unsubscribe link. SendGrid provides a “Subscription Tracking” app that automatically adds this link to your emails. When someone clicks that link within their email, they are added to your “unsubscribe” list. The next time you send to the address as part of your regular newsletter list, we will not attempt to send to email addresses that appear on this list. Sending to an address that has unsubscribed from your mailings can be detrimental to your reputation. Typically, transactional emails do not need to include unsubscribe links; however, marketing newsletters should always include one.

Enable Click, Open, and Subscription Tracking in the “My Apps” Section of your SendGrid account

Each of these metrics is important to consider when evaluating the performance of your email campaigns. Overall campaign performance should essentially guide your decisions around customer communications, and a full picture is essential to making smart decisions.

SendGrid customers are able to access all stats from our web interface when logged in as a user at or through our Event Webhook.

We’d love to hear about the role that email metrics play in your everyday business decisions. How often do you evaluate your email statistics? Once you’ve evaluated, how do you employ the insight you’ve gained? Let us know on twitter or facebook.

Expert advice and insight about all things email including best practices tips, examples, and advice for marketers, developers, and everyone in between.