A guide to email marketing metrics

As a marketer, you craft your email campaigns with meticulous attention to detail. You ensure that your email lists are complete, customers are segmented, email content is personalized, the call-to-actions are in the right place, and that your email design is appealing. But how do you know if it’s working? The answer is your email metrics. 

Depending on your goal, email metrics let you objectively assess the effectiveness and ROI of your campaigns. As email marketing has grown, the delivery tools and services have scaled to offer more focused insights into campaign performance. Here’s a list of crucial email metrics you should be familiar with, and how you can optimize your campaigns by improving them.

Open rate

The open rate is the percentage of the total recipients who have opened your email. Here’s how you can calculate it:

Why is the open rate important?

Your open rate is a good indicator of engagement.  A high open rate means your recipients find the subject lines appealing or are well aware of your brand, and open your emails. A low open rate means lesser people are reading your message and converting.

However, the reported email open rate is never completely accurate because delivery services rely on image loading to track if an email was opened. Email clients often block the images from loading, resulting in all such emails to be considered unopened. An email with a click-through is counted open even if its images didn't load to reduce this inaccuracy. With this in mind, using the open rate as a comparative metric works better. You can compare an email's open rate with the previous one you sent to the same list and draw some learnings on better subject lines.

How to improve your email open rate? 

Keeping the following points in mind could positively impact your open rates.

Focus on high deliverability

The recipient will never open your email if it doesn't reach their inbox. Therefore, it’s essential to ensure you have good email deliverability (discussed later) and avoid spam filters.

Experiment with timing

What day and time you choose to send your emails can impact your email open rates. What might be a good time to send emails on Monday, won’t be the same for Wednesday. Keep on experimenting with your sending schedules to arrive at the one that works best for you.

Work on your subject lines

Subject lines are crucial when it comes to open rates. Pick a subject line that is personalized, appealing, and makes the recipient want more. Always A/B test your subject lines to understand what resonates with your subscribers.

Send emails that your subscribers like

Subscribers always remember a bad, irrelevant email. If you've sent one in the past, the chances of them opening your next email are far less. Keep learning from your previous emails to create emails that resonate with your recipients.

Clickthrough rate

Also known as CTR, Clickthrough rate is the percentage of the total recipients who clicked at least one link in the email. You can calculate it using the following formula:

Make sure you don’t overcount. For the above formula, we count the number of recipients and not the total clicks. If a person clicked on two different links or clicked on a link twice, they would still be counted only once. 


Why is CTR important? 

When your subscriber clicks on an email link, it means they found your email relevant and were compelled to take the next action.  A high clickthrough rate, therefore, indicates the effectiveness and relevancy of your email messaging.

How to improve your clickthrough rate?

It’s not a one-time process. You need to keep experimenting and analyzing the results to improve your CTR. Here are a few tips on bettering your clickthrough rate:

Optimize for mobile

More people open emails on mobile than desktops. It means you need to ensure that your email is mobile-responsive.

Use effective CTAs

Go beyond the usual “click here” copy on your buttons. Make the CTA copy more clear, descriptive, and compelling.

Test your content

Test different variants of your email copy or CTA copy with small sample segments (10% of your audience). The better performing variant should be sent to the remaining subscribers.

Email delivery rate

Email delivery rate measures the percentage of emails that didn’t bounce and were received by your subscriber’s email server. This means it landed in your subscriber’s inbox. It can be calculated as:

Importance of email delivery rate: 

What’s the point of spending so much time creating emails if they don’t even reach your subscriber. According to the Direct marketing association, email as a channel offers an ROI of up to £42.24 for every  £1 you spend. How will you ever yield the highest results with your campaigns if they don’t even reach your recipient?

Understand more about the importance of email delivery rate, how email delivery works, and more in this comprehensive guide to email delivery.

How to improve your email delivery rate?

To appear as a legitimate sender to ISPs (Internet Service Provider), you need to follow good email practices. Here are some of them:

Level up your mailing infrastructure

Make sure your email server configuration is correct. Deploy a dedicated IP if you’re sending a massive volume of emails. Set up a postmaster and abuse mailboxes for your domain and monitor them regularly. Be sure to maintain good mail server security from open relays and open proxies. Alternatively, opt for an email service provider to get rid of the complexities of maintaining a good email infrastructure.

Reduce spam complaints 

Each ISP maintains a threshold for spam complaints. A high number of spam complaints could get you blocked by specific mailboxes. To avoid this, sign up for feedback loops to remove email addresses with complaints on time.   

Email deliverability

Now that we ensure that your email is reaching the recipient’s server, it doesn’t necessarily mean it reached their primary inbox. Some of the emails are routed to the spam/bulk folders, decided by the inbox provider. Email deliverability measures the percentage of your sent emails that end up in the recipient's primary inbox.

Learn all you can about email deliverability, sender reputation, infrastructure, and more in the ultimate guide to email deliverability.

Importance of email deliverability 

Same as email delivery, your efforts in email campaigns would be of no good if your recipient doesn’t realize that you have sent them an email. Most of us never even open our spam folder. These emails will just burn a hole in your pocket and skew your metrics, with no return.

How to improve email deliverability?

There are a lot of email best practices and guidelines that impact your deliverability. Here’s what you need to keep in mind.

Maintain a high sender reputation

A good sender reputation points out to the email service providers that you are a trusted sender. Therefore, it increases the likelihood of your emails not being labeled as spam and making it to the recipient's inbox. Keeping your email lists updated and free from hard bounces, having a consistent email volume, and avoiding spam traps are a few ways to improve your reputation. 

Improve your sending infrastructure and authentication

Infrastructure and authentication protocols are a checklist of technical guidelines that establishes you as an identified and trusted sender. Moving to a dedicated IP, using separate IPs for different email streams, and monitoring feedback loops keep your reputation healthy. DNS records like SPF, DKIM, and MX help email service providers ascertain that you’re not a spammer and have a valid identity, thereby keeping you in their good books.

Focus on your email content

What you send in your emails and how you tune them for the recipients decide how well they will engage with them. Email service providers reward senders with a good engagement rate by keeping their reputation high. In short, send emails that are personalized and offer value to your subscribers.

Conversion rate

The conversion rate is the percentage of subscribers that complete a desired goal. A goal can refer to your subscriber becoming a customer, renewing a subscription, or opting for a callback request.

Importance of conversion rate

Tracking the conversion rate allows you to measure the return on investment of your campaigns. It helps you understand what percentage of users are completing goals that drive business for you. By tracking the conversion rate, you can understand your emails/website/app's success and identify opportunities for improvement.

How to improve your conversion rate?

When it comes to email, there are two types of conversions - micro (open rate, click rate, CTRs) and macro (revenue, sales, signups). To maximize impact on the bottom of the funnel, you need to optimize both micro and macro conversions. Here are a few tips: 

Segment your email lists 

Sending emails to segmented lists improves their relevance. You can segment your email lists based on subscribers’ geolocation, demographics, interests, purchase history, and more such factors.

Personalize communication

Personalized emails are proven to drive more engagement and revenue. Personalization of emails includes using the subscriber’s name and other information. More advanced personalized emails include sending personalized triggered emails based on the subscribers’ behavior on product pages, shopping cart, etc.

Build more trust 

Sending relevant, creative, and engaging content will make your subscribers open your emails more often. It also ensures your emails land in the inbox instead of the dreaded spam folder.

Bounce rate

The bounce rate is the percentage of emails returned to the sender because they could not be delivered. There are two kinds of email bounces - hard bounce and soft bounce. A hard bounce means that the email can't be delivered permanently. A soft bounce, on the other hand, is temporary and can be reversed. It can be calculated:

Why is the bounce rate important? 

While it may seem like the bounce rate does not impact your goals, it is essential to optimize and improve your email delivery. After all, if your emails don't reach your subscribers - everything else about your campaign fails too.

How to reduce your bounce rate?

Here are some key practices you need to follow to reduce your bounce rate:

Practice good email list hygiene 

Clean your email lists regularly. Remove all the non-responders, unengaged, and invalid email addresses. Set a frequency as to how often you will do it and keep at it, religiously.

Use double-opt-in 

Using double-opt-in works in two ways - 

  • ensuring you only get valid email addresses, 

  • only the interested subscribers receive your emails.

Monitor your email delivery

A high bounce rate could signal issues with email delivery. Tracking your email delivery puts you in a position to take action before you incur substantial damage to your sender reputation.

Unsubscribe rate

Unsubscribe rate is the percentage of the total recipients who unsubscribe after receiving one email. Unsubscribers are the people leaving your lists because they either don’t find value in your emails or aren’t interested anymore. You can calculate your unsubscribe link this way:

What is the importance of the unsubscribe rate?

It’s essential to keep a check on your unsubscribe rate to track your subscriber growth rate. A higher than average unsubscribe rate for a particular campaign requires a close assessment of the email messaging and offer.

How to reduce the unsubscribe rate?

You can bring down your unsubscribe rate by keeping the following points in mind:

Keep a healthy email frequency

Sending emails too frequently can start irritating your subscribers. The best way is to test and understand your subscriber’s behavior. You can also maintain subscription preferences, letting the subscribers specify how frequently they want to hear from you.

Segment your audience

You can segment your list based on demographics, interests, or behavior to create targeted email lists. It helps you send relevant emails to your audience, thereby keeping your unsubscribes low.

Personalize your emails

Your subscribers find personalized emails better than a standard, templatized communication. The latter gives them more reasons not to engage with your email and opt for them.

List growth rate 

List growth rate tracks the rate at which your email list or number of subscribers grow. This isn't something that email delivery services calculate for you. You can figure this yourself depending on the period you consider for the growth:

Why is list growth rate important? 

A good list growth rate can help you improve your email marketing ROI. A growing number of subscribers means a top-of-the-funnel improvement, resulting in more visitors, leads, and, thus, more customers.

How to improve your list growth rate? 

You must keep a tab on how your email list is growing. You can keep increasing the growth rate by following these tips:

Bring down your unsubscribes

Unsubscribes bring down the net impact of adding new subscribers. Keeping you unsubscribes low ensures a good list growth.

Publish more gated content

When your visitors download a content piece from your website, you can ask for their consent to add them to your email list so that they can continue receiving similar resources.

Use lead magnets

Try to maximize the opportunities of converting your traffic to subscribers. Show an opt-in popup to returning website visitors, using content download offers strategically are ways of doing that.

Action rate over time

Action rate over time measures the level of engagement of your emails based on the time of the day. Sending many many emails over a prolonged period of time can help you find the right time for your emails. The action rate over time can be determined by breaking down your open and click-through data by different hours of the day. As shown below, the report shows you the number of click-throughs received at different hours of the day.

Why is the action rate over time important?

The action rate gives you a good insight into your subscriber’s email behavior. It points out to you the best times to send emails to your subscribers so that the chances of being opened and acted upon are high.

Improve your action rate over time

Use your action rate data to find the slots where your subscribers engage the most with emails. Scheduling emails for those hours, and avoiding periods of low engagement can improve your action rate.


With brands using email marketing extensively, you need to evolve continually and better user communication to get the subscriber's attention.  The only way to ensure your next campaign performs better than the last one is to rely on data. All these email metrics let you understand your subscriber's behavior and preferences better. A good email marketing automation allows you to track all the parameters as you scale your marketing campaigns. Your email marketing's success relies heavily on it, along with always keeping an eye on the right metrics.