How to Measure Transactional Email Performance

December 01, 2022
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How to Measure Transactional Email Performance

Businesses pay a lot of attention to marketing email performance to measure return on investment. But we often don’t monitor transactional emails in the same way. 

This could be because it’s easy to forget about these automated emails after you set them up or because you send them from a platform that doesn’t offer easy access to analytics. 

Regardless, it’s crucial to track transactional emails to understand whether these reach customers’ inboxes, provide relevant information, and keep recipients engaged with your business.

But what metrics help you measure the success of transactional emails? In this post, we’ll go over the key performance indicators (KPIs) you should track. 

Why should you measure transactional email performance?

Measuring transactional email performance gives you an idea of your email program’s health, especially regarding deliverability, and flags any issues you need to address. 

Transactional emails are a critical part of your program because these directly tie to customers’ actions and contain information about their purchases or account, making them highly personalized

Transactional emails include: 
  • Purchase confirmations 
  • Shipping notifications 
  • Identity verification 
  • Password resets 
  • Account notifications
  • And more
Due to the email content, it’s crucial that these reach the inbox and give customers the information they need. Otherwise, these could create a negative experience and get in the way of customer loyalty. 

For example, say a customer makes a purchase from a business for the first time but never receives an order confirmation because it lands in their spam folder. This would likely erode their trust in the business, and they’d be reluctant to purchase from it again. And if the sender doesn’t monitor their deliverability and reputation metrics, they may not realize customers aren’t receiving these crucial emails. 

Transactional email performance metrics 

Let’s dive right into the most important email metrics to determine your transactional email success. 

Emails processed 

The number of transactional emails you send can give you an idea of your business activity. For example, purchase confirmation emails give you immediate insight into how your ecommerce business performs in sales. 

And while the processed metric tells you how many emails you attempted to send, you’ll need to pair it with the following metrics to get the total number of successfully delivered emails. 

Emails delivered 

Once an email is processed, meaning your email service provider (ESP) attempts to deliver it, the recipient’s mailbox provider needs to accept it. This is what delivered measures, and it’s a crucial metric to understand whether providers accept or reject your emails.

After the receiving mailbox provider accepts your email, it determines what to do with the message, such as placing it in the primary inbox, a secondary inbox tab, or the spam folder. Learn about the steps you can take to improve deliverability and ensure your messages reach the inbox.

Bounced and blocked

What about the emails the receiving provider rejects? Bounced and blocked metrics tell you how many emails your ESP didn’t successfully deliver and why. 

Bounced indicates that the provider didn’t deliver the message because the email address doesn’t exist. Also called a hard bounce, this could be because the customer entered it incorrectly or the address is no longer valid. Ideally, hard bounce rates should be lower than 0.5%, and an email validation tool can help you keep bounces low by detecting false entries when the user enters their email address. 

Blocked indicates that the provider didn’t deliver the message for another reason, such as an issue with the sending internet protocol or the message content. Learn about block classifications to understand why an email wasn’t delivered. 

Unique opens

The unique opens metric tells you how many recipients opened your emails, making it an essential KPI for any email program. 

On the marketing side, unique opens can help you understand the effectiveness of your subject lines and relevance of your emails to recipients. And on the technical side, unique opens can help you detect deliverability issues. 

For example, if unique opens are suddenly down, even though you’ve made no changes to your sending behavior, it could indicate that more of your emails are landing in the spam folder. This could be a sign to look at other signals, like spam complaints and sender reputation, to find the cause. 

However, some providers, like Google and Apple, now have security measures that can create false or anonymized opens. This happens when providers load images from your emails ahead of time, which your ESP could count as an open. Learn how this can affect your metrics and how to identify these opens from Apple and Google


When it comes to transactional emails, some calls to action (CTAs) are more important to track than others. For example, order confirmation emails often include a link to track the package for the customer’s convenience. But as a business, you probably don’t need to know how often recipients click on tracking links. 

Other emails, like requests for reviews after a purchase or identity verification emails, have CTAs you’ll want to track to gain insight into customer engagement. 

For these emails, add click-through rate (CTR) to your list of KPIs. CTR tells you the percentage of clicks on links within your emails based on all your successfully delivered emails. This metric helps you understand whether the content effectively encourages users to take the desired action. 

Measure email performance with Twilio SendGrid’s deliverability insights

Now that you know which email metrics to measure, the next step is to figure out how to access these insights to understand how successful your transactional emails are. 

The right ESP will offer intuitive email metrics dashboards that place these KPIs at your fingertips to view delivery rates, opens, clicks, and more—that’s where we come in. 

Twilio SendGrid offers just that with various dashboards that enable you to monitor email performance easily. These include deliverability insights, where you can track the metrics discussed in this post, and mailbox provider statistics, where you can get more granular insights by provider. 

Learn more about how to get started with deliverability insights, and try SendGrid for free to begin measuring email performance. 

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