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12 Vital Email Engagement Metrics To Track ROI

Email Metrics to track ROI

Email is often the gateway to activate customers acquired from other channels. It’s also the number one touchpoint for relevance and reach. But without tracking the latest email engagement metrics, your email campaigns risk falling short of their promise.

While some of your clients may think of emails as archaic remnants of the 2000s, email marketing is becoming increasingly critical to marketers–especially compared to the last four years. In fact, a well-executed email campaign delivers a 4200% ROI, which is more than any other marketing channel today. 

graph showing percentage of brands who depend on email marketing


Let’s explore how to use email engagement metrics to tap into more revenue and get your clients a bigger bang for their buck in 2022.

This article covers: 

What Are Email Engagement Metrics?

Email engagement metrics are pieces of data that tell you which of your emails are “working” and which aren’t. They tell you how your audience is interacting with your emails, which links they click on, what types of emails they enjoy, and what makes them tick–aka, convert. 

Why Are They Important?

With a reported $42 return for every marketing dollar spent, your clients have high expectations from their email campaigns. And they hired your agency to generate leads and turn them into new customers. But you can’t succeed in the latter if you’re sending the exact same message to everyone. You know that. Email engagement metrics allow for better personalization, segmentation, and delivery–you can improve your content and consistently deliver killer email campaigns. 

Without the right email marketing metrics, you won’t have the right tools to make your plans a reality. Consider the fast-changing purchase behaviors and industry trends that affect your email campaign success. For instance, there is a shift towards:

  • Privacy

  • Personalization

  • Automation

  • Sensitivity to world events

5 Changes Affecting Email Marketing Today


Email marketing is now essential for business success. 


Personalization and automation are absolute necessities for running email campaigns.


New privacy measures are forcing marketers to seek out first-party data to personalize their email campaigns. 


52% of marketers spend over two weeks completing a single email. Being agile is critical to email marketing campaign success and avoiding burnout. 


Email marketing must keep track of world events, stay culturally sensitive, and even join in on the conversion. (Think BLM, the war in Ukraine, MeToo.) 

With all these variables and more, how can agencies isolate the cause of a campaign’s success–or flop–without aligning numbers to the creative process? 

In short, email engagement metrics will tell you why you’re bringing in the results that you are–and how to build upon them.

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12 Email Marketing Metrics to Track to Measure Email Engagement

This list will help you uncover which email marketing metrics to track based on your clients’ goals. We will also discuss what email engagement metrics tell us about our campaigns and how they align with three main campaign goals:

  • Gauging and Keeping Interest

  • Measuring Campaign Success

  • Optimizing Campaign Delivery 

Goal 1: Gauging and Keeping Interest

Open Rate

Open rate is the number of times subscribers opened your email. This is calculated each time the same subscriber opens an email.  

Unique Open Rate

The total number of times your email is initially opened. This doesn’t include the cases where the same subscriber opens the same message repeatedly.  

What to do about it: When a subscriber opens an email, it means that your Subject line and Preview text enticed them to do so. More brand recognition, better positioning, and a not-too frequent influx of emails help increase email open rate

Bounce Rate

This refers to the emails that weren’t successful. There are two causes of email bounces:

  • Soft bounces are caused by an error on the subscriber’s end, like having a full inbox.

  • Hard bounces are due to invalid email addresses and are likely lost contacts.

What to do about it: A healthy bounce rate is 2%, anything more, and you should look into your email acquisition process. For example, having subscribers confirm their subscription will help validate email addresses. List hygiene is also important to remove hard bounces and consistent soft bounces.

Unsubscribe Rate

The number of lost subscribers within a certain period. 

What to do about it: Figure out which campaign made them unsubscribe, and even go back to see their acquisition source and email history to better understand what broke along the customer journey. It might also be that you’re sending emails too often or not sending topics that interest your subscribers. 

Top Email Unsubscribe Reasons

Complaint Rates or Spam Rates

This is particularly important to watch out for as it can negatively affect your future email deliverability. Ensure the emails you’re sending out were to people who you have permission to email, either express or implied.  

What to do about it: Keep this number below 0.02% to avoid any warnings. Above 0.04% for a single email and your account could be suspended. Permission is one of the biggest impacts on the complaint or spam rates, so if you're hovering near the edge, consider implementing a double opt-in process.

ClickThrough Rate

This email marketing metric refers to the percentage of recipients who clicked on at least one of the links in your email. This is calculated by dividing the number of people who clicked something by the number of delivered emails multiplied by 100. A solid CTR is between 2-5%.   

What to do about it: If your CTR is on the lower end, there are a number of things you could test out, like including fewer CTAs and text links, improving buttons, and ensuring your emails are more visual with clear, streamlined text. Also, check the open rate (above) if people don't open the email, they certainly aren't going to click on anything.

Click-to-Open Rate (CTOR)

This is the percentage of subscribers who click something in an email in relation to those who opened it. A healthy CTOR is between 20% and 30%, depending on industry averages. 

What to do about it: This is the best metric to measure how effective your email’s overall messaging is. A high CTOR means you’re connecting with your active audience, so if this number is low, take a look at your audience segmentation and tailor the message accordingly. 

To Summarize the Key Metrics for Gauging and Maintaining Interest: 

Email Engagement Metric

What It’s Really Saying: 

What To Do About It

Open Rate

“You got my attention.”

Continue creating Subject lines and Preview Texts that deliver value and incentivize an open. A good benchmark is 20% and above, depending on the industry

Bounce Rate

“You can’t reach me here.”

Ensure systems are in place for subscribers to confirm their emails when they first sign up to avoid misspellings. 

Unsubscribe Rate

“I’ve lost interest.”

Better email segmentation will ensure you’re sending topics that interest the subscriber. Look at your email frequency to see if there’s a correlation between unsubscribe rate and email frequency. 

Spam Rate

“This is spammy.”

Do quality control over your emails and ensure you’re sending emails only to those who explicitly signed up. If this number goes up, it could also be due to email frequency. 

Click-through Rate

“I’m interested enough to browse.”

Facilitate skim-reading in your emails and use click-worthy (not clickbaity) subject headers to easily lead the subscriber to your goal.  

Click-to-Open Rate

“I’m picking up what you’re putting down.” 

Tailor the message to your audience to connect with them and keep CTOR high. 

Goal 2: Measuring Campaign Success

Revenue per Email (RPE)

This tells you how much revenue your email list generates. Calculate your total revenue from a campaign and divide it by the number of recipients minus the number of ones that bounced back. 

What to do about it: If your RPE isn’t wowing clients, you’ll need to look back at everything from your CTAs to improving the customer segmentation and user journey.  

Purchase Rate and Conversion Rate

This is also a very important metric, as it tells you how many people actually followed through after clicking on your CTA. This email marketing metric refers to a conversion, which could be a purchase, signup, downloading a document, you name it. What matters is that it fulfills the goal you set for your clients and moves the customers along the purchase journey. 

What to do about it: It all really comes down to this metric, so you’ll need to take a look at your email’s mobile-friendliness, optimize all copy for the correct email segment, and use behavioral triggers to send the right emails to the right people at the right time.  

List Growth Rate

Just as it sounds, this is the rate at which your client’s email list is growing. Calculate this by taking the number of new subscribers, subtracting the number of those that unsubscribed, and dividing that number by the total number of email addresses in your client’s email list. Multiply that by 100, and you’ve got your list growth rate. This helps your agency gauge how the engagement rate (e.g., unsubscribes) is impacting the total list growth.  

What to do about it: In your client reports, display this number in a line chart to show a positive upward tick. Your clients will really be looking for this number as it means you’re drawing in new leads to their business. If this number is not growing, then you need to look at the mechanisms you have in place to grow your email newsletter and other email capture points as well as what could be causing enough unsubscribes to completely offset new subscribers.

Forwarding and Sharing Rate

This is a great metric to track your subscribers’ loyalty. When they become your client’s brand advocates, they’re helping you spread the word about your client. This falls into the later stages of the buyer’s journey in email marketing

What to do about it: Look at what gets shared the most, and include similar materials in your emails to broaden your reach beyond the subscriber. Try providing something your subscribers would like to share, like a coupon, a fun quiz, a useful tip, or an incentive. 

To Summarize the Key Metrics for Measuring Campaign Success: 

Email Engagement Metric

What It’s Really Saying: 

What To Do About It

Revenue Per Email

“You had me at Hello.”

Impress your clients by giving your RPE the spotlight in your client reports. Analyze past emails to see what generates more revenue than others. 

Conversion Rate

“You got me.” 

Use heat maps to see where people tend to browse more and optimize your emails with clearer CTAs and streamlined messaging. 

List Growth Rate


Show this off your clients’ growing community in your reports as an upward trending line chart. 

Forwarding and Sharing Rate

“This makes me want to be a good samaritan/pay it forward/tell my friends.” 

Put have social share buttons to facilitate sharing. 

Goal 3: Optimizing Campaign Delivery 

Engagement Over Time/Action Rate Over Time

This email marketing metric measures the overall activity of your emails throughout the day to help you narrow down your ideal send time.    

What to do about it: If you don’t have previous data to benchmark from, start out with industry benchmarks and see which times deliver the best results.

we miss you email campaign example to inactive email subscribers

Inactive Rate

This rate indicates the number of subscribers who haven’t opened or clicked on a certain number of emails, or during a certain interval. 

What to do about it: Set up a re-engagement campaign. A ‘We’ve Missed You!’ email can go a long way in giving them an offer they can’t refuse or some useful tips and information. With most email automation platforms, you can have this kind of campaign sent automatically when the subscriber reaches a specific inactivity threshold. 

Relapse Rate

When an email subscriber becomes inactive again after having successfully been re-engaged, it’s called a relapsed subscriber. Your relapse rate is how often this happens. This is an email benchmark to track, so you know which re-engagement campaigns have flopped, so you can better investigate why. 

What to do about it: It might be a good idea here to open lines of communication in alternative ways. For one, they should be in a stream that receives fewer emails. Also, consider sending out surveys to relapsed subscribers so they can tell you how to do better. 

To Summarize the Key Metrics for Optimizing Campaign Delivery: 

Email Engagement Metric

What It’s Really Saying: 

What To Do About It

Engagement Over Time

“I don’t open emails before 10 am.” 

Use this metric to find the ideal send time. 

Inactive Rate

“I am numb to your emails.”

Put these subscribers into a re-engagement campaign. 

Relapse Rate

“Nevermind. You’ve lost me again.”

Send them fewer emails, and give them the opportunity to explain their sentiments in a survey. 

How to Measure Your Email Marketing Success

Measuring your email campaign’s success boils down to having the right tools to streamline your workflow, automate the data-retrieval process for quick, actionable insights, and report results to clients. 

To consistently reach these goals, you’ll need to keep track of the right engagement metrics–in real-time–to gear your email marketing campaigns up for continued success.

Essential Email Reporting Tools

Now that you know which email metrics to track based on your clients’ goals, it’s time to present them in a way they’ll understand. All of this is made easier with tools to help you automate a lot of the email marketing reporting process. 

Email Metrics Report Template 

Whether your agency uses Mailchimp, Constant Contact, Hubspot, or any other email marketing platform, tracking all your email KPIs for each of your clients can be a daunting task–but not if you play your cards right and automate the whole data-retrieval process. 

Your agency needs an efficient way to report on results for each email campaign to give you information that will help you maximize your ROI and overall campaign success. 

email marketing report

Start with our Email marketing report to show the value you’re driving towards their business. Try it free for 14 days!  

What’s the Best Email Service Provider (ESP)?

While there are many email service providers, what it really comes down to is which is best for your agency and your client's objectives. Choose the one that you’re most comfortable with, and has an integration with your reporting software. AgencyAnalytics integrates with popular ESPs such as Active Campaign, MailChimp, Salesforce, and Hubspot

This allows you to pull in your clients’ revenue data, pipeline data, as well as email engagement metrics automatically in a dashboard for easy analysis.

email marketing integrations

Key Takeaways  

Since email engagement relies on an everchanging set of factors that change with time, like industry trends and your audience’s particular expectations, agencies need to keep a constant finger on the pulse to ensure their emails deliver results. 

Email marketing campaigns are a continual work-in-progress. Display benchmarks in your client reports to keep track of growth and stay ahead of targets. 

Prove your ROI by combining your clients’ email marketing metrics alongside their other marketing channel data to show the true value your agency is bringing to the table. 

Like this article? Find out more about eCommerce Email Marketing Strategies

Written by

Melody Sinclair-Brooks

Melody is a marketing manager, writer, and startup consultant. She builds communication bridges thru multichannel storytelling, strategic partnerships, advertising, and go-to-market strategy.

Read more posts by Melody Sinclair-Brooks ›

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