Email marketing offers many advantages over other forms of marketing, but measurability has got to be one of the main ones. 

From monitoring open rates and click-throughs to measuring unsubscribe rates, it provides a thorough overview of your audience’s interaction with your messages.

That, in turn, allows marketers to make informed decisions about what content works best and when to make changes to their campaign.

And yet, many either overlook some of the key email marketing KPIs or ignore their relevance entirely to the detriment of their campaigns. 

To me, that feels like driving a car without the steering wheel or building a house without blueprints. 

There’s just so much valuable data to be gained from a properly monitored email marketing program, that it genuinely upsets me to see otherwise successful marketers failing to use email analytics to their full potential.

So, what are these key email marketing metrics that you should always be monitoring? What are email marketing KPIs and how can you measure them? 

Let’s get started, shall we?

What Are KPIs?

Computer screen showing important email marketing KPIs

KPIs – short for Key Performance Indicators – are a group of performance measurements.

Businesses use KPIs to measure the effectiveness of their business processes.

In email marketing, KPIs represent quantitative measures that you can monitor and refine over time to ensure your emails remain effective.

For the most part, marketers tend to only analyze metrics like open rates or unsubscribe rates, thinking that these are the only KPIs that matter.

And while it is true that those metrics are important, there are additional email marketing KPIs that can tell you a great deal about the success or failure of your email program. 

That said, let’s examine the top 9 email marketing KPIs you should be tracking whenever you launch a new campaign.

Open Rates

Many marketers obsess over their email open rates, and perhaps rightly so. After all, we can’t be talking about a successful email marketing campaign if people don’t open our emails in the first place. 

However, this particular KPI can be somewhat misleading. See, you might be getting a high-open rate, but if people aren’t actually clicking through to the content that you’re sending them, it won’t matter.

The only meaningful conclusion you can extrapolate from this metric is to see whether your email subject lines are working or not.

Therefore, what you really want to be looking at is click-through rates (CTRs). A higher CTR means that your audience is responding to the content that you’re sending them and taking action.

Click Through Rates (CTR)

The click-through rate is the percentage of recipients who click on a link within your email.

As mentioned above, this particular email KPI indicates whether your audience is responding to your content and is taking action. 

If your emails are getting high CTRs –  more than the average for your particular industry – this is a great indicator that your email campaign is working.

If not, you’ll want to continue making tweaks to the copy, design, and layout of your emails.

In any case, doing your CTR calculation on a regular basis is a great way to gauge the effectiveness of your email campaigns.

Email Delivery Rates

Deliverability is another super important email marketing metric. It measures how well your email service provider (ESP) delivers your messages to your target audiences. 

A low deliverability rate indicates that your email campaigns are going into spam folders. It could also indicate that your ESP is blocking emails from your IP address.

This is not uncommon for marketers who send mass emails in Gmail or any other free ESP.

Free ESPs are not exactly renowned for their high deliverability rates due to their sensitive spam filters and other limitations. 

To maximize deliverability, you should be using dedicated email marketing software like Mailvio. Built by marketers for marketers, Mailvio maximizes deliverability with pre-warmed IP addresses and allows users to dramatically improve their sender reputations.

Mailvio's landing page

Low deliverability rates can also indicate that it’s time for you to do some list cleaning and get rid of:

  • Inactive subscribers, 
  • Invalid addresses, 
  • Spam traps, etc. 

Unsubscribe Rates

This is another common metric that shows whether or not your subscribers are open to hearing from you again.

In other words, it shows the percentage of your subscribers who have opted out of receiving any further emails from you. 

A high unsubscribe rate is a clear indication that your emails are falling on deaf ears.

In that case, you might want to clean up your email list and remove inactive subscribers to improve deliverability and sender reputation.

A low unsubscribe rate, on the other hand, tells you that people are still interested in what you have to say.

That said, this particular email performance metric is not the most reliable when it comes to gauging the quality of your email list.

The truth is, many people who don’t want to receive any more emails from you will simply ignore them, rather than go through the hassle of unsubscribing.

Because of that, it is much better to gauge subscriber engagement by conversion rates (more on that later) and clickthrough rates before you start removing inactive subscribers from your list. 

Conversion Rates

Conversion rate is one of the most important email marketing metrics. Why? Because it measures how many people clicked on your links and then completed the desired action.

Having said that, it’s important to know that conversions don’t necessarily mean making a sale. Depending on what you are hoping to achieve with your email campaign, it can also mean:

  • subscription for your newsletter or webinar
  • registration for an event or a demo
  • a download of a piece of content (your lead magnet), etc.

At the end of the day, conversion rates provide you with unique insight into your ROI.

Knowing how much you’ve spent versus how many subscribers are converting will tell you whether the money you invested into your email campaign is actually paying off.

Bounce Rate

The email bounce rate measures how many of the recipients on your list failed to receive your email.

There are two types of bounces in email marketing, including hard bounces and soft bounces. 

Hard bounces are permanent bounces.  They occur when you send emails to email addresses that no longer exist or to invalid email addresses with typos.

With hard bounces, it’s advisable that you immediately remove those email addresses from your subscriber list because they can impact your overall email deliverability.

Soft bounces, on the other hand, are temporary and are indicative of errors on the receiving end. For instance, a soft bounce may occur when a recipient’s server is down or their inbox is full.

With soft bounces, you don’t need to worry about your reputation because the email will eventually reach its destination.

IMPORTANT TIP: A good way to decrease your bounce rates is to use a double-opt-in. That will ensure that you only send emails to people who verify their email addresses and consent to receiving your emails.

Spam Complaints

Keeping an eye on your spam complaints, as well as your unsubscribe rates, will quickly tell you if you are doing something wrong. 

As mentioned above, there will be many instances where people will mark your emails as spam rather than going through the hassle of unsubscribing.

However, if both of these KPIs are going up, you might want to review what you’re sending out and make changes.

Is there something technically wrong with your emails? Are you not adhering to email copywriting best practices? 

Whatever the case, ESPs don’t take kindly to constant spam complaints and can very well take action against you and block your email account.

List Growth Rate

This one’s a bit self-explanatory, but for the sake of clarity, here it is:

The list growth rate is an email marketing metric that shows you the rate at which your email list is growing.

So, how does one calculate this email marketing KPI?

To measure your list growth rate, you simply take the number of new subscribers and subtract the number of unsubscribes. Next, you divide that number by the total number of addresses on your email list and multiply it by 100.

The thing with email lists is that they degrade like crazy over time. 

To counter this trend, check out these 35 list-building techniques. If executed correctly, they will help you create an active, engaged subscriber base that will remain loyal to your brand.

Email Sharing & Forwarding Rates

In newsletter analytics, your email sharing and forwarding rates will give you the percentage of people who either:

  • shared your email on social media sites, or 
  • forwarded it to someone. 

This email marketing KPI is an excellent indicator of the overall quality of your content. It will let you know how many loyal brand ambassadors are spreading the good on your behalf.

It might sound insignificant, but the rate at which people share your emails online can make a big difference for your brand.


Because it will help you acquire new leads and ultimately grow your business.

Final Thoughts 

Proper email campaign tracking involves more than just knowing how many subscribers you have or what your open and click-through rates are.

It requires a comprehensive and thorough approach to monitoring the nine essential email marketing metrics outlined in this article and acting upon them accordingly. 

Only then will you be able to create a data-driven, goal-oriented marketing strategy that will drive sales and profits for your business.

And if tracking email KPIs is not something you excel at (or are looking forward to), there are tools that can automate much of the process for you. 

We recommend that you try Mailvio, a full-service autoresponder that provides incredibly detailed analytics and tracking capabilities at one hell of a price!

But don’t take my word for it. Just go ahead and sign up for a 7-day free trial and see for yourself.

Do you have some email marketing reporting tips to share with us?

If so, please let us know in the comment section below. 

Neil Napier

Neil Napier is the co-founder of Mailvio. Neil started his entrepreneurial journey in 2012 out of necessity to keep his visa in the UK, when he failed to keep his visa he moved to Finland and started his career as a serial entrepreneur and super affiliate. With over $10 million USD in revenue generated, he is a sought-after expert entrepreneur, copywriter & product creator.

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