Email performance can be measured in many ways. Look at any email marketing tool and you’ll find dozens of metrics you can use and monitor. But blindly trusting the metrics they give you can result in a misinterpretation of the data, leading to bad decisions. Or you might give more weight to things that are imprecisely, making you focus on things that aren’t really so important at the end of the day.

To actually succeed in email marketing, you need to focus on two things: deliverability (your ability to reach the recipient) and content performance (your ability to convince the recipient to reach the goal you set up).

In this article, we’ll take you through all the most important metrics for measuring the success of your email campaigns, along with benchmarks to help you understand what numbers you should aim for.

How to measure email marketing success

Step 1. Understand everything you can measure in email marketing

We will help you understand what metrics can be measured, what pitfalls you can encounter when evaluating them, and what decisions the metrics can lead to.

Step 2. Set up goals

What are your goals for email marketing? Do you use it for customer re-engagement, for sending a bulk newsletter to your audience, or for targeting individuals with personalized messages based on their recent behavior? 

Different campaigns will have different goals. You should not expect every email to bring you revenue. Sometimes, all you are looking for is to re-engage with the customer and explain your unique selling propositions, hopefully leading to purchase later.

Step 3. Define KPIs

Once you know the goals for your campaign, you can start with defining KPIs. It’s important to focus on both “positive” KPIs – such as revenue uplift or open rate uplift, while also looking at minimizing “negative” KPIs – such as keeping your unsubscribe rate below a certain level.

Step 4. Track metrics

Tracking the metrics should be automatic with most of the modern email solutions, or customer data platforms (CDPs) that offer execution. The benefit of using a CDP is that you can see all email related actions in a single customer view.

Step 5. Evaluate

Evaluating email metrics is quite tricky – some of them need to be looked at daily, some weekly, and others you can only check monthly.

Check these daily: open rate, open rate variation, bounce rate, soft bounce rate. 

These are the metrics that might help you spot incoming / growing problems. 

Check these weekly: overall campaign performance, campaign conversion & revenue reporting, click-through-rates, spam-complaint rates, unsubscribes and active audience trend.

Check these monthly: opens per customer, revenue per customer, mobile open rate, email client share, spam score checks. 

Step 6. Improve

Knowledge of benchmarks will help you prioritize what needs to be improved. If you don’t like your conversion rates for a newsletter, but you’re still beating benchmarks, then there might be another area to focus on where you can get a bigger improvement for the same effort. 

To set up a strategy, you have to be confident in the numbers you see reported. You have to understand how the metrics influence each other and what could go wrong by trying to improve one area. 

It’s completely normal to feel overwhelmed by the sheer size of the reporting – there are lots of different metrics, and it’s difficult to even know where to start. If you feel this way, then just start at the beginning of the funnel: your customers, your audience criteria, and your email frequency. Once you’re happy with this part of the funnel and you’re getting results you like, you can move on to the next steps: delivery rate, open rate, click rate, and eventually revenue.

Remember that you’ll need to be patient. Big changes, especially in email, take time. Be patient and set reasonable timelines, and don’t expect miracles after two campaign sends.  Keep this in mind when communicating with your team or senior stakeholders. Email marketing is a complex system, and it depends on more than just your performance. There are external factors at play. You need to test and work towards finding what works for you, your goals, your customers, the mailbox providers, and those trying to fight spam

But before you do anything else, you need to understand email marketing metrics. So let’s take a look at what they are and how they’re defined.

Email Marketing Metrics

Before you even send a campaign and start measuring campaign-related metrics, you need to understand the audience that you market to. 

Email audience trend

As you gain subscribers, you also lose subscribers – this is a natural process. Knowing that your audience is declining, and knowing this early, will help you prevent bigger revenue issues 3 months down the line – it enables you to take actions, to understand why subscribers are leaving and what you need to change.

Active audience trend

It’s also vital to monitor the growth or decline of your active audience as well. These are the subscribers that engage with most of your emails, bring the most revenue, and according to best practices, are the only ones with whom you should communicate with a high frequency. 

Catching any issues early on and setting up a good re-engagement program should help you avoid any shrinkage of your active audience.

Delivery rate

Delivery of an email is usually the first thing measured after an email is sent – it means that your email was accepted by the recipient server. In the case of a bigger deliverability issue, you would see your delivery rate drop – this might indicate that you are being blocked completely.

As long as your database is clean, you should be achieving a 99% delivery rate or higher, although you might see lower delivery rates on programs such as double opt in, or a welcome program, where new email addresses enter your list.  

A delivery rate below 97% should get your attention. You might need to check how you’re collecting email addresses. Using real-time validation at the point of collection can be helpful here.

It’s important to note that a high delivery rate does not mean high inbox placement – your email could be getting delivered, but winding up in junk/spam folders, where the recipient won’t notice it.

Hard bounce rate

The bounce rate informs you about hard bounced emails: emails that are permanently unreachable. You should automatically exclude any bounced addresses from your list. Failure to do so will lead to your emails being blocked completely. 

A high bounce rate can be caused either by already being blacklisted, or by sending to inactive emails (this is more common). You can find out what’s happening by looking at status messages or code that was sent back to you. 

Some email providers will block a domain with 1%+ bounce rates for bulk campaigns, as it indicates bad email list health. In general, keeping your bounce rate below 0.5% is a benchmark you should aim for.

Soft bounce rate

Soft bounce rate informs you about temporary issues in your emailing. This doesn’t mean it’s not important to monitor, as it can hint at bigger issues. If you ignore these warnings, you will eventually encounter hard bounces and a drop in delivery rates. 

Frequent causes for soft bounces are temporary blacklisting, full mailboxes, connection errors, and greylisting. To avoid these, make sure your email list is clean and that you use best sending practices. You should aim for a less than 0.5% soft bounce rate. 

If you encounter a big spike in soft bounces, it could be a mistake or bad filtering on the recipient domain side. You can try solving this with your ESP, who will be able to reach out to the recipient domain.

Open rate

Open rate is the 2nd most important deliverability metric because it shows you both that emails are reaching the customers inbox, and that either the brand or the subject line caught their attention. Most brands calculate this as unique opens, since counting all opens can skew the results.

Senders with good list health and an engaged audience typically reach 30-40% open rates on bulk emails. The golden standard to reach is at least 20%+.

On automated or triggered personalized campaigns, you might see open rates between 40% and 70%. This is possible with smaller audiences, microsegmenting, and very relevant content.

The open rate is determined by displaying a 1px x 1px image at the top of the email. When the email is opened, the image is downloaded, which lets the tool know who opened an email and when it happened. However, there is a downside to this method: if images are blocked by the email client, there is no way to track opens.

Your open rate can be improved by various factors you can A/B test: the time of sending, the subject line used, the sender name, pre-header or personalisation in the subject line.

Total open rate

This metric, when compared to the previous open rate metric, will help you understand how many customers are coming back to reopen an email. This is helpful for finding out whether customers are coming back to emails with, for example, USPs or loyalty program information. If they are, you might think about sharing that information in an easier to find way, so they’re not searching for old emails.

Open rate variation

When you compare open rate results between different domains, you might see that one domain is performing much worse than your best performing one. For example, Gmail might have open rates of 30%, but Hotmail only reports 14%. This would hint at inbox placement issues with Hotmail. 

You will always see some difference due to different types of customers using different mailbox providers, but if the difference is 30% or more, it deserves more attention.

Opens per customer

If you are trying to adjust your email frequency, this metric might come in handy. Select a time period for which you are calculating the metric (we usually look at the last 7 or 30 days) depending on how engaged the audience is and how frequently you are sending already.

It’s hard to establish a benchmark here, since it’s very dependant on the frequency of your emailing.

If you send 15 emails a month, but the average opens per customer in 30 days is just 1.6, you might have to reconsider your sending frequency. You can still send a higher frequency to the most engaged audience, but tune it down for the less engaged. 

Sending fewer emails with the same opens per customer would also mean an increase in your open rate! You can use prebuilt frequency management policies in Exponea.

Engagement time

Understanding when your customers are engaging with your emails can prove very helpful for campaign timing and getting better conversion rates. You should send emails when customers are ready to open them, which can vary a lot from individual to individual. But even aggregated results can show you where there’s room for improvement. An example of how to measure this metric is in part 6: Useful reports.

Mobile open rate

Are you optimizing your content for desktop, mobile or both? Do you properly test all major mobile devices? You might find out you are spending a lot of time optimizing your emails for the 0.1% of your subscribers that use Outlook, but the majority of your revenue might come from the 70% of your subscribers that are iPhone users! 

Although it’s not always possible to identify the device or type of devices used to open an email, you should try to do it where possible. This is usually parsed from “user-agent” and some tools, including Exponea, will do it automatically for you.

Click-through rate

This metric shows how many customers, out of all those that received an email, clicked on the content. This is essentially reporting on two things at once – how many customers opened an email and how many out of those clicked. It is mostly useful at evaluating the overall success of a campaign and comparing the performance of different campaigns.

Low CTR might mean two things: either the customers were not convinced to open the email, or they opened it but weren’t convinced to click through. To help you understand which case you’re dealing with, you need to overlay this metric with the Click-to-Open rate, which we describe next.

A great CTR to aim for is 4%+, although on average brands typically see something just under 3%.

Click-to-open rate

While similar to the previous metric, this metric is calculated based on emails opened, not delivered. This means that it better reflects the performance of the content of your email. 

If you see low CTR, but high CTOR, this usually means the customers were not convinced to open an email, but once they did, they engaged. You can fix this by looking at why the customers are not opening the email.

You might have great content, with an above-average CTOR, but if the subject line was underperforming, most people won’t see the awesome content you prepared.

On the other hand, low CTOR means the content did not perform very well. Even if you targeted the correct customers with an eye-catching subject line, the content was below the expectations of your customers. 

Companies often achieve a 15% CTOR, which is a good benchmark to aim for.

Unsubscribe + spam complaint rate per email

Reporting on unsubscribes is important for understanding the other side of the email business: how many people completely lost interest in your marketing efforts, or worse, your brand? 

Your campaign might have performed very well thanks to an eye-catching subject line. But what if there are many people who after opening the email, felt misled by the content and unsubscribed immediately? Most of the time, those subscribers will have been lost forever.

To lower your unsubscribe rates, you should limit your sending frequency for less engaged customers, and make your emails relevant to the customer receiving them. You will always have some unsubscribes, but spikes in the numbers should warrant an investigation on your side.

Unsubscribe rates should be below 0.5% on a campaign level. We also usually recommend including spam complaints into this metric, as these are also considered unsubscribes, just done differently.  This is a user who thinks your email is spam and marks it as such, which  means you should immediately stop sending them any emails. Spam complaints should be less than 0.01% of your send.

Conversions & revenue & AOV

The correct attribution of conversions will make or break your email revenue reporting. Most companies today use last click attribution, with an attribution window of 24 hours or 3 days, depending on email frequency. If you are sending 2 emails a week, it would be more accurate to select a longer time attribution window than a brand sending emails every day.

Looking at revenue and AOV alongside the number of conversions will help you understand if certain campaigns are driving high value purchases, or if your triggered scenarios, like an abandoned cart email, are working. Is the AOV higher than before implementing them?

Conversion rate

Understanding how campaigns create revenue is important for prioritizing which campaign should be further developed, which content ideas work, and which customer segments perform the best in email marketing.

Some brands also look at conversion rate from opens instead of emails delivered. This better reflects the effectiveness of the content and the offer itself, but it should not be used exclusively.

A conversion rate benchmark for newsletters is 1%+ and for triggered emails is 3-5%+, with some very specifically targeted or heavily incentivized emails achieving 15%+.

Revenue per open

Calculating revenue per open is important when changing the high level strategy of your emails, audience management or frequency capping. Sometimes, these changes may lead to more opens being generated, so you should know whether revenue per open is increasing or decreasing.

This is not an important metric by itself, but should be looked at when evaluating revenue changes.

Revenue per subscriber

Revenue per subscriber is very important for 2 key areas: measuring the effectiveness of your email marketing in terms of costs and revenue, and measuring the impact of high level changes to your email strategy.

Time spent viewing email

Some tools allow you to report on the time spent reading an email. This helps you to understand whether the content is important to the customers, and whether the customers can quickly find what they were looking for. A short time of reading and a click means that the customer found what was important almost instantly. On the other hand, a long reading time and no click might show that the content the customer was looking for was not there.

As email read times are increasing recently, especially for mobile, you might find that your emails are too short, and you can fit more content in.

This is a metric to keep an eye on, but not a business-critical metric.

Spam Score

There are two types of “spam score” metrics: one that evaluates your content spam score, and one that evaluates your “sender score”, which is dependent on your domain or IP.

Your content spam score looks at several factors: your image to text ratio, the use of “spammy” keywords, whether you include malicious links, and the technical setup of the email (e.g. missing DNS records like SPF or DKIM), and others depending on the ISP.

The ideal is to keep this score as low as possible – you can measure it using a dedicated tool.

Email Client Share

This metric is harder to measure, but it’s still helpful. It looks at the share of different email clients your customers are using. 

This is parsed from “user-agent” information that the sender can see by using an open tracking pixel – but it doesn’t always result in valuable insights. While you will be able to distinguish between iPhone and Outlook users, Gmail will report one string for all different clients using Gmail, no matter whether they’re reading on their desktop, app or mobile version of the website.

Once you find the breakdown of your audience, you can allocate appropriate effort to optimizing for different email clients. If Apple Mail makes up 80% of your opens and you need to send out an urgent email, you know what device you should test on.

Email marketing goals & KPIs

Now that you know the metrics, how can you use them to improve your marketing? In the end, you need to decide what your goals are – and that will determine how you use the metrics. But we’ll share a few ideas with you here. Before setting up your goals, you should be absolutely clear on the state of your reporting, and understand your key challenges based on what your metrics are telling you. 

Your emailing goals don’t need to be entirely based on metrics. They can be based on something more abstract, like wanting to include more personalisation in your newsletters. The important thing here is that your results need to be quantifiable and measurable. This is where you come back to the metrics we discussed above. You will need to set different KPIs based on which metrics are important for your goals.

Now let’s look at some goals that email marketers frequently set. We’ll start from the most complex one and then look at some more specific ones. We’ll also give you some KPIs to focus on for each goal.

Goal: I want to increase the revenue I get from email marketing by X% in Y months

This is the most common, but also the most complex, goal that you can set for yourself. It is influenced by many factors, so it is usually wiser (and easier) to break it down into smaller steps and multiple KPIs.

Let’s start at the end of the funnel: a conversion. Conversions on the web or in an app can come from email in two ways: either directly from a click in an email, or indirectly (a customer gets an email but doesn’t make a purchase immediately, but later they remember the content from the email and come directly to the site to make a purchase).

There is no straightforward way to measure email’s influence on the latter scenario, so we need to start with a quantifiable goal: an increase in clicks and click to open rate.

You can improve these metrics with the following tactics:

Test your email

Test the content, formatting, and images on multiple devices. Make sure your readers can engage with the content once they open the email.

Make it easy to convert.

Don’t hide a button at the bottom of the email. Highlight the conversion goal multiple times and work on your CTA button – it’s your moneymaker. Set the right expectations at this stage.

Personalize

Make the content personalised and relevant to the customer – whether that means targeting based on their favorite category, or using advanced recommendations that choose the best products for that particular customer. This tactic is usually the most effective one.

Let customers give feedback.

This can be done by encouraging a direct email reply (you might have noticed that “noreply@brand.com” emails are slowly disappearing), giving customers a simple poll about the content, or setting up a customized preference control center that allows customers to select the topics they are interested in and set the frequency with which they’ll receive emails.

You should also look at increasing the number of email opens. We cover that in a separate goal breakdown below.

A metric that’s one step earlier in the funnel is the number of emails sent out. Increasing this number can also increase your performance, but it can also backfire quickly. Sending as many emails to as many customers as possible is a short-sighted decision nowadays, and your email reputation will be penalized in a matter of weeks or even days. 

So how can you increase the number of emails sent while keeping best practices in mind? You can check out the active audience size goal below, but apart from that, here are a few things to keep in mind:

• Don’t overcommunicate – 99.99% of customers do NOT want to hear from you twice a day, every day. Limit the number of emails that you send out, and get into the head of your customer to better understand how many emails they want to receive.
• To achieve this, take time to build your active audience, i.e. customers who have engaged with your emails within the last 90 days. This is the audience you can communicate with the most frequently without getting penalized by mailbox service providers. On the other hand, customers who have not opened an email of yours in the last year are not very likely to open your next email, and sending to them can hurt your reputation.
• Start using frequency management. Establishing which customers receive how many campaigns per week or month can lead to multiple metrics being improved. Even with a small drop in the volume of emails sent, you might still see an increase in the absolute number of opens, clicks and revenue.  
• Build different types of campaigns. You have many different types of customers: some are bargain hunters, some focus on social responsibility, some are always looking for something new to wear. Try a few different types of campaigns, and start to segment users based on which campaigns they usually click on, or what they’re interested in on your website. In essence, this means making your content relevant to your different audiences.
• Automate based on the customer journey. Identify customer journey touchpoints where it makes sense to communicate: registration, their birthday, their first return. These campaigns can churn out revenue during the whole year. They take time to build, but they don’t need to be checked frequently (although you should aim to update them at least every few months). This can increase the number of emails you send out, while keeping the content relevant and personalised.

Goal: I want to increase my active audience size by Y(%)

Two things influence your active audience size: customers becoming part of your active audience by engaging with an email, and customers leaving it by not engaging.

Increasing engagement.  Start by improving your sign-up process. Is it as simple and straightforward as GDPR allows? Are the customers clear on what they are signing up to? Once they sign-up, do they receive a welcome email that sets the expectations for the content they will start receiving from that day? If they don’t open the email, do you try to re-engage them with personalised communication, or do you just start churning out newsletters?

Re-engaging customers. Do you make sure that customers have a good reason to re-engage? If you know a customer is about to leave your active audience, there are a few things you can try. Offer an incentive, showing what they missed out on by not opening your emails (create “FOMO”). Make sure to capture customers with re-engagement campaigns not just at the 90 day mark, but at different times too: 150 days, 180 days, a year. Don’t be afraid to A/B test various incentives and messaging at this stage.

Goal: I want to increase my open rates by 30%

The open rate metric can be quite misleading, and the overall number doesn’t tell you the whole story. It’s important to establish a benchmark between different mailboxes. This helps to rule out any deliverability issues before you try to improve content. 

If the variation in open rates for different mail providers is more than 30%, e.g. Gmail reports an open rate of 20% while Hotmail reports 11%, you should focus on improving your inbox placement with Hotmail. This can be achieved by following the best practices outlined in our Ultimate Guide to Email Deliverability.

If you are sure you don’t have any major deliverability or inbox placement issues, you can proceed with content improvements. Anything the customer sees is fair game for improvement. Here are some items worth checking.

“From” name

Is it obvious at first sight who the email is from? Try A/B testing which branding works best for you (using a personal name in the “From” might work for some more informal brands – e.g. Peter from Exponea). Most of the time, keeping it simple is the winning variant. People like consistency here, so don’t change the sender name too often. This might get you incorrectly flagged as a phishing or scam attempt by the recipient.

Subject line

Here you can really flex your creative muscles. This is the most visible element of the email, so make it personal! Use any knowledge of the customer you have to make the subject line relevant, but not creepy. Focus on the brands, categories, and products the customer likes. If possible, do an automatic A/B test – test 3-4 variants on a small portion of your database, wait for a few hours, and then send the winning variant to the rest of your customers.

Pre-header text / preview text.

Although slightly less visible than the subject line, customers still notice it. Make sure to use this space to “preview” what the content of the email will be like. You definitely shouldn’t show the following message: “If you can’t see the email properly, click here to view in browser” – this is a waste of valuable space. 

Send time

The last thing that is visible to the customer at first sight, and this influences where your email is in the inbox. If you send your email at 6 AM, and the customer usually checks their emails after work, you might already be in the 10th position. You need to use your knowledge of when a customer opens their emails and be sure to send them at that time so you can land at the top of the inbox.

All of these improvements will lead to an increase of open rates. Of course, the person you’re sending to is also important. When it comes to the recipient, the same principles from the previous goals apply: be careful not to over communicate, be relevant to the individual customer and make sure the frequency is acceptable.

Useful reports

There are two major reports that will tell you most of what you need to know about your emailing, including both deliverability performance and campaign performance. These reports were created in Exponea, but you should be able to recreate them in the analytics program of your choice.

Email domain report

The first one is the email domain report, which shows you metrics for specific recipient domains. This will help you see any deliverability issues with a particular mailbox provider – and you can use open rate variance metric here. If a certain provider shows 30% lower open rate than the other, this is most likely due to bad inbox placement. Similarly, if there is any spike for soft bounces or hard bounces, you should look into what is causing those issues.

Campaign report

The second perspective, which uses mostly the same set of metrics in a different format, is the campaign report. You can get this report by using the previous Email domain report, but in rows, you should use “campaign > campaign_name” instead of “email_domain”. You can also add “campaign > subject” as an extra row, in case you want to see the subject lines used, or if you tested various subject lines.

This allows you to monitor how your campaigns are doing, e.g. how is different content influencing the click rate, how is a different subject line affecting open rate, etc.

Soft bounce / bounce report

If you spot any problems in the campaign / email domain report, you can use the following report to investigate further. This will help you understand where soft or hard bounces are coming from: is it bad email list health or is your content being blocked?

Here’s the short video preview how you can set up such a report in Exponea:

Once you find out what the most common issues are, you can start to solve them. A good starting point is our Ultimate Guide to Mastering Email Deliverability. Take a look at the sections about segmentation and deliverability factors in your control.

Open and click time report

To help you understand when customers are opening or clicking  on your emails, and whether this is in line with their usual shopping time, you can build the following report. You will see most of the opens and clicks happen after sending the campaign, but you might find out that this isn’t when your customers typically do their shopping. You can then use optimal send time prediction to manage this for you, or manually adjust the campaign launch times.

At first sight, we can see a high open-to-purchase ratio before lunch, when the email is sent. But then we can see that customers are opening fewer emails but still shopping.

If we hide opens from this view and look at clicks only, we can see that there are spikes in clicks in the morning and late evening, but they don’t correlate with when purchases are happening.

Here you could benefit from using optimal send time prediction, as this would make sure every customer receives an email at their optimal time. If this prediction isn’t available to you, you can also use this for the segmentation of morning and evening shoppers, and send campaigns at two different times for these two segments.

Here’s the short video preview how you can set up such a report in Exponea:

Where to go from here?

Email analytics is a rich field and there’s a lot to digest. With this article as a guide, you can start working on improving your metrics across the funnel, starting from the top.

If you want to improve your emailing skills, consider registering for an Exponea Academy course. Regular courses on email marketing (and other topics) are offered by our seasoned instructors.

For most brands, email is just one of their many communication channels. If you want to learn how to best incorporate other channels into a comprehensive plan, take a look at our ebook on building an omni-channel strategy.