three up arrows from envelopes for increased email open rates

How to Increase Email Open Rates: Your Complete Guide


Want to learn how to increase your email open rates? Let’s consider some important facts:

There are 300 million M&Ms produced every day. There are over 75 billion LEGO bricks sold each year. There are around 1.7 billion websites.

And…about 300 billion emails are sent — every single day.

The average person receives over 100 emails every single day. That’s a lot of competition for attention, which is why figuring out how to sustain or increase your email open rates continues to be one of the most important marketing challenges.

In fact, our Inbox Success report found that 54% of marketers identified email open rates as one of the top three metrics for measuring the health of an email marketing program.

In addition to the competition from other emails and other forms of media, you’re also competing with fatigue and inbox overload. That’s a lot to deal with! But before we get to some of the strategies you can use to increase your email open rates, let’s define a few terms.

Jump to a section in this article:

What is an email open rate?

First, let’s define some standard email marketing metrics and how they relate to one another. Here’s how email open rates and related metrics are defined and calculated.

Open rates

Email open rates are calculated by dividing the total number of emails opened by the number sent. It’s a pretty simple statistic. Send 1000 emails. 200 are opened. You have a 20% open rate.

Open reach rate

This metric quantifies the percentage of your list that was reached over a series of emails. Let’s say you send three different emails to promote a new product and each has an open rate of 20%. Perhaps you only reached 20% of your total audience — three times each. But if every email was opened by a different 20% of your list, you actually engaged 60% of your total list — one time each. Open reach rate measures the percentage of unique people engaged.

Click through rates (CTR)

The click-through rate is calculated by dividing the number of clicks on your email content by the total number of emails delivered. So again, if 1000 emails are sent and 30 people open and click somewhere on the email, that’s a 3% CTR.

Click to open rates (CTOR)

The click-to-open rate is in many ways more helpful than the CTR. It tells you how many people who actually opened an email also clicked on it. Using our previous examples, the CTOR would be 15%, because out of 200 opens, 30 people clicked.

What’s a good email open rate?

Overall average open rates aren’t enormously useful, because every email list is unique. But for the sake of having a place to start, here’s what some of the major email service providers (ESPs) report for their overall averages.

ESP Average Open Rate
Constant Contact
Campaign Monitor

This makes the overall average open rate just under 20%. And, of course, the data changes all the time.

So, is that useful? Do you feel better or worse based on your open rates? Well, you shouldn’t. Because this overall email open rate masks dramatic differences when you break it down into industries, countries, types of emails, and many other factors.

Average email open rates by industry

Consider just a few industries, taken from an email benchmark report from GetResponse:

Industry Open Rate Click-to-Open Rate (CTOR)
Non-profits 30.85% 11.67%
Restaurants 30.09% 9.94%
Real Estate 28.37% 8.52%
Health Care 26.88% 11.19%
Arts & Entertainment 25.97% 12.22%
Financial Services 24.97% 12.92%
Agencies 24.02% 9.84%
Health & Beauty 23.58% 11.52%
Retail 23.28% 11.54%
Publishing 22.17% 19.36%
Travel 22.48% 7.17%
Technology 19.87% 12.63%
Internet Marketing 14.97% 11.10%

Source: GetResponse Email Marketing Benchmarks (Q3 2019 – Q2 2020)

  • Nonprofits and restaurants average email open rates of just over 30%.
  • Arts and entertainment email open rates average just under 26%.
  • Retail and Health and beauty email open rates average around 23%.
  • And at the bottom of the list is internet marketing, with an email open rate of under 15%. Figures.

The point is, open rates vary widely by industry, so it does little good to compare your open rates with an average that blends them all together. A better idea is to benchmark open rates for your email program and work to improve them.

Email open rates by device

Finding reliable data for this one is difficult, so we won’t pick and choose any specific numbers. But what’s clear is that about half of emails are opened on mobile devices, even more for younger people.

So often in email marketing (as with any marketing) it comes down to knowing your audience. If a large percentage of your audience is young, it’s even more important that your emails are optimized for mobile devices.

Average email open rates by type of email

  • Transactional email open rates are above 80%, because they are relevant to an action the user has taken.
  • Marketing emails, by contrast, have open rates in the 20% range.
  • Abandoned cart emails were found in a Klaviyo study to have open rates of 41%, far higher than the industry average.
  • And welcome emails were found by GetResponse to have a whopping 86% open rate.

Again, the reasons behind these aren’t hard to figure out. When someone subscribes and enters a welcome email series, they’re expecting something from you. When they get it, they open it.

So the types of emails you send, who you’re sending them to, and many other variables greatly influence the open rates you should hope to see.

Email open rates and subject lines

The subject line, pre-header, and sender name can all be seen before your email is even opened. These are what you have to work with to boost your open rates. Let’s look at subject lines first.

Best practices for writing effective subject lines

Subject lines are to emails what headlines are to articles. Careful consideration and clear communication are important.

Be honest — no cheap tricks

Email readers hate being misled by clickbaity subject lines. Don’t promise something in your subject line that your email doesn’t deliver. That email might get opened, but the sour taste you leave in your reader’s mouth makes it less likely they’ll open the next one — assuming they don’t unsubscribe.

Don’t be spammy

We all get spam, so you know how to recognize it. Don’t do what they do. Don’t use weird characters, or all caps, or tons of punctuation. Your from name is your best weapon against being misidentified as spam, but don’t write subject lines that make your readers wonder if this is real.

There was a time when certain spammy-looking subject lines could land your email in the junk folder. That’s not as much of a concern any more. These days, your sender reputation and domain reputation are much more important. However, improving email deliverability certainly can help you get more opens. Subscribers won’t open most emails that end up in spam.

Use subject line split testing

Got a couple of ideas for a good subject line but unsure which would increase email open rates? Test it. Subject lines are one of the most important and impactful things to split test in email marketing.

Doing just one or two random split tests now and then isn’t actually that useful. You need a methodology that is used consistently and delivers data and results over time. For instance, you can set up tests that send emails to only a portion of your intended audience. Whichever email gets the best open rate then goes to the rest of the list. Certain ESPs will have this type of subject line split testing built into the platform.

Avoid repetition of language or strategy

With email, variation is critical. If you put ‘Star Wars’ in your subject line, you’ll probably get a ton of opens because people are always intrigued by pop culture references. But if you put Star Wars references in multiple emails every month, your readers will quickly wise up to your act.

That’s something to watch out for in split testing, too. If you find an email subject line that worked well, it doesn’t mean you should use that same approach over and over again. Use it judiciously, selectively. And find other strategies that work well, too.

For more advice, check out our 5 tips to creating a killer subject line.

Should I put emojis in subject lines?

Special characters work and then't don't work n subject line

The GetResponse benchmark study found very little difference in open rates with emails that had emojis versus ones that did not. Subject lines with emojis saw a slightly higher open rate of less than 1%. The difference in CTR was practically zero.

If you’ve never used an emoji, there’s a good chance your first email that uses one will have a higher open rate. But if you start doing it every time, the effect will quickly wear off. Emojis are just another tool for subject lines that you can use now and then if you wish. But they don’t have any special email superpowers.

If you do use them, are you confident that they’re showing up correctly on the many different email platforms your readers use? If your emoji turns into a mess of bizarre characters in the subject line, you can almost guarantee a terrible open rate. Here’s an article about how to use emojis and other special characters in subject lines.

Also, Email on Acid’s Campaign Precheck process allows you to view your subject line on various devices and platforms. This is as important — if not more so — than previewing how the actual email will look, especially if your subject line contains anything other than normal characters.

Do character counts matter?

According to AWeber, the average email subject line is just under 44 characters long.

The GetResponse benchmark report found that longer subject lines got higher open rates than shorter ones. Now, don’t take that as a license to write 500-character subject lines. The most important consideration is whether or not the subject line shows up in full. If the last half of it gets cut off because of length, then it doesn’t do you much good. It could even do you harm if your truncated subject line inadvertently results in an awkward phrase or profane word.

For that reason, be sure to front-load your subject lines with the most impactful and important words or information.

And remember that on mobile devices, fewer characters are usually visible than on desktops. To avoid subject lines getting cut off on mobile devices, shoot for a length somewhere between 35 and 45 characters. That should work on major clients such as Gmail.

Types of subject lines that increase open rates

Again, what you want to do is vary your approach. No one subject line strategy works best all the time, because everything gets stale, and different messages require different tactics. Here’s a quick rundown with examples of various types of subject lines you can use:

  • Curiosity: “Can you believe this happened?” or “See what our CEO said when she saw these numbers.”
  • Activity-based: “Did you enjoy the webinar last Friday?” or “This might go well with your last purchase.”
  • Contrasting, unrelated ideas: “Luke Skywalker and watermelons” (pop culture references are effective too) or “Email open rates and the Eiffel Tower.”
  • Deadlines and urgency: “Conference registration deadline is tomorrow” or “Your coupon code expires at midnight!”
  • Authenticity/casual language: “Monday” or “Our call.”

The goal is to make the person feel a need or desire to find out more, to arouse some kind of emotional response. I want this. I need this. I wonder about this. This is how you want the reader to react. It’s a split-second decision.

And, underlying all of these is relevance and trust. If they know who you are, and they trust you, then these sorts of subject lines will produce consistently healthy open rates.

Email open rates and personalization

When most people think or hear about personalization, they imagine using the subscriber’s first name. Like emojis or other subject line strategies, putting the person’s first name in the subject is just one tool at your disposal. Use it too often, and its effectiveness dies a slow death.

But personalization is really about customizing the content based on what you know about the subscriber — which is often much more than their name. Here are some other ways to feel more like a neighbor than an intruder:

Use demographics

Which demographics are appropriate depends on your company and the information you have on your email subscribers. You could use the city they live in, their age, special dates like birthdays and anniversaries, home values, number of kids, and so much more. A subject line like “Kids leaving for college soon?” speaks to people who fall into that demographic. That message is personalized to them.

Previous activity

This could be purchase behavior or other forms of engagement. A subject promising “a special message to everyone who attended last year’s conference” speaks to a particular subset of your list.

Unresolved product engagement

Do you have customers who create wishlists? Do you track abandoned carts? You can send emails personalized to these situations, such as one offering special discounts on items on their wishlist. Quality email marketing data is the foundation of a complex and effective strategy. To personalize at this level, you need an email system that can access all this customized data. See 35 of the best email automation platforms.

Adjust the “from” name

This may not always be personalized in the literal sense, but changing up the sender or ‘from name’ in your campaigns has proven to be another effective tool to increase email open rates. This works because it feels like it’s from someone specific, rather than the usual name people come to associate with your company.

You can even have fun with this, such as sending an email from your mascot if you have one, or a well-known thought leader at your company.

You can also use different departments as sender names, with the main company name used in all of them. For example, JCPenney menswear vs JCPenney kids.

Adjust the reply email address

Some of the worst reply emails are no-reply@businessname and admin@businessname. Deeply impersonal addresses like these make the recipient feel like a robot is emailing them, not a person. We may enjoy robots in movies, but for the most part, we hate being emailed by them.


Many companies invest heavily in marketing and processes to make customers feel like they’re not just another number. A no-reply email address is sending the exact opposite message.

Using these kinds of addresses can also lower your reach as many subscribers filter out “no-reply” addresses from their inbox. That’s a pretty good indication of how customers feel about this practice. Using one can also damage your sender reputation and might even violate anti-spam laws.

Plus, why wouldn’t you welcome a chance to engage with customers? You probably encourage people to comment on social media, so why wouldn’t you do the same with your email marketing?

Instead, use a person’s name — or a department name like billing, sales, or service — as your reply email address and make sure it’s well monitored so customers can interact. Learn more about subject line personalization

Preheader text: the unsung hero of email open rates

email preheader

What is preheader text? Preheader text is the text that appears directly below or to the right of the subject line, depending on which device the subscriber is using. The subject line is typically bolded, and the preheader text is not. Here’s a case study showing an 8% lift in open rates when a preheader was added.

The GetResponse benchmarks found preheader text could increase email open rates as much as 3%. It also resulted in a more than a 1% higher click-through rate, from having preheader text – ANY preheader text. Why?

Because if you don’t write preheader text, the device will find somewhere to pull that text from. It might be the opening lines of your email. It might be from the footer. It might be the alt text behind your logo or header. Ugh. Wherever that text gets pulled from, one thing you can be sure of is that it will not relate well to the subject line, and will not increase the chances of the email being opened.

Just as you take time writing subject lines, do the same with preheader text.

How to use preheader text to increase email open rates

Here are five preheader text ideas, along with what not to do.

The main idea is to make the subject line and the preheader complementary to each other in some way. If the subject asks a question, the preheader could begin to answer it. If the subject makes a promise, the preheader should suggest the fulfillment of that promise, or give a reason why that promise matters. If the subject mentions a sale, the preheader could list a few items that are available.

Use the preheader to deepen or enhance the subject line, but without giving closure. Start the story, but don’t finish it.

If the subject line is the pilot, the preheader is the co-pilot. Can you fly a plane without a co-pilot? You can, but if the pilot gets in a jam, the co-pilot is the one who saves the day. Because of character limits, the subject line isn’t always enough to compel a reader to open the email. The preheader helps push that person with a little extra curiosity or detail.

Length matters. Find out how to optimize preheader text for different email clients and devices.

Because devices display preheader text differently, Email on Acid has made preheader text preview part of Campaign Precheck, our automated email checklist. You want to know how well it’s showing up, and if any characters are being cut off. Sometimes, that’s okay if it only happens on certain devices, but you need to know if the message is clear enough to compel an open.

List segmentation and email open rates

Segmenting Your Lists

In many ways, segmentation is just one very effective form of personalization. If you create a segment that includes only people who have made two or more purchases within the last year, you can send them targeted subject lines that appeal to their affinity for your products.

Clearly, they enjoy shopping from your company or find your products very useful, and you can take advantage of that with subject lines targeting people like them. For example, “special coupon code for loyal customers”. That’s personalization through segmentation.

How strategic segmentation leads to more opens

Mailchimp found list segmentation could increase email open rates by 14%, and it leads to a 100% higher click-through rate compared to non-segmented emails.

Do it well, and segmentation is one of the best tools for increasing email open rates. Besides buying habits, you can also segment by demographic information, signup dates, levels of engagement, expressed areas of interest, conferences attended, lead magnets downloaded, and much more.

For each of these segment types, you’ll be able to send targeted subject lines and preheaders that speak to that group of users and generate more opens.

If you look deeper at the Mailchimp data, they also found fewer bounces, fewer unsubscribes, and fewer spam complaints. So not only does segmentation increase positive metrics, it reduces the negative ones.

Segmentation question: is a bigger email list better?

Imagine that you’ve won the lottery. Would you take $20 million as a lump-sum payment or $670,000 per year for 30 years? Similar totals, but you’ll likely pay far fewer taxes with the second option. And, you’re less likely to blow it all in a few years.

Bigger isn’t always better.

The same may be true with email lists. Here, the issue is list quality. Want an email list of 50,000 names that opens 15% of your emails. That’s 7,500 opens. Or, would you prefer a list of 30,000 that opens 30% of your emails? That would be a total of 9,000 opens.

Over time, the second list will likely produce more revenue. And, it will earn you a better sender reputation.

That’s why we recommend, in general, using a double opt-in approach to list building, rather than single opt-in. What’s the difference?

Explaining the double opt-in strategy

With double opt-in, when a person joins your email list, they receive an email that asks them to confirm they want to join your list. With a single opt-in, they’re added automatically with no confirmation. Why does this matter?

Well, a lot of people sign up for email lists just to get the freebie you’re offering. Other people use ‘junk’ email addresses that they never check. Some people may even use disposable email addresses (aka burner emails) that are completely fake. A double opt-in approach will result in a smaller list that grows more slowly, but it will be of much higher quality. Everyone who opted in really wanted in — enough to click on that confirmation email.

The bottom line is, if a person won’t confirm their email for a list they signed up for, they aren’t a very good prospect.

The double opt-in approach will reduce your spam reports. You’ll have more accurate data — no bots will be able to join your email list. And all your email addresses will be correct, with no typos.

Single opt-in lists cost more, too, because many email service providers charge by the size of your list. With a bigger list that includes a percentage of worthless emails, you’re paying for it.

What is sender reputation?

Email deliverability is one of the most under-the-radar factors in achieving higher email open rates. It’s based in part on your sender reputation.

If you have a poor sender reputation, which is based on your IP, more of your emails will start to be labeled as spam. This can lead them to be sent directly to the spam or promotions folders rather than the main inbox of your subscribers. It can also lead your emails to be blocked completely, never even seen.

Needless to say, that makes it tough to open them.

This is why you need to regularly scrub your email list of inactive addresses. Someone who hasn’t opened an email in over a year is probably done with you. Low open rates and low engagement affect your sender reputation.

If you’re getting hard bounces, this usually means the email address is no longer active. Hard bounces affect your sender reputation. Clear those emails off your list and you’ll be protecting your reputation and boosting your open rates at the same time.

Email open rates and send time optimization?

circular clock showing optimal email send time

‘Time’ can refer to the time of day, or the day of the week.

In both cases, the overall data is murky. What you need to do is perform testing on your specific audience. Why? Because different audiences are more active and more responsive to emails at different times and days of the week.

At Email on Acid, we’ve found no difference in the open rates of our emails on weekends and weekdays. But on the weekend, we found that the skim rate was significantly higher, which meant fewer people read the message, though people were also less likely to unsubscribe.

Again, it really depends on your specific audience. B2B audiences, in general, tend to be more responsive on weekdays during business hours. You could test for variations between emails sent at the start of the day, around lunch, and near the end of the day.

A weekend send could help you avoid the clutter of weekday emails, but if you find your skim rate to be high like ours, a higher open rate might not be the advantage it appears to be.

For other companies, evenings might get better open rates. Consider a restaurant sending out limited-time coupon offers. Most people eat out at night, so that email would probably get more traction in the afternoon or early evening, as an impulse buy. You might find you get more email engagement on weekends with certain types of consumers.

To optimize your send times, test them repeatedly, over an extended time with many emails, and look for trends.

Does email frequency affect open rates?

The email benchmark study from GetResponse found the highest open rates with companies sending one email per week, declining a bit with each additional email sent per week.

So, does that mean you should never send more than one email per week? Well….no.

Remember, increasing email open rates isn’t the only metric that matters. If you’re trying to get signups for a webinar, picture this scenario:

One business sends one email per week about the webinar for three weeks, averaging a 30% open rate, and each email gets a 2% signup rate for the webinar. Another business sends three emails per week for three weeks. That’s nine emails versus three. Those emails average a 23% open rate and a 1.5% signup rate.

With nine emails — even with lower open rates and CTRs — you will get more eyeballs on your emails, and more cumulative signups for your webinar.

Open rate is not the only metric that matters. Consider your goals for your email marketing campaigns and look for a balance between high open rates and maximum engagement. The kind of campaign mentioned above is particularly aggressive. It might provide a short-term benefit of more webinar registrations, but sending at that pace will likely come with negative effects like unsubscribes and even abuse complaints — not to mention the drain on resources to create and manage the campaign.

Optimize your inbox display

As we’ve touched on a few times, a wacky inbox display will hurt your open rates. Special characters, emojis, preheaders, and other items in your subject line, sender name, and reply email address will look different on different devices.

Email on Acid’s primary goal is to empower companies to pretest all their emails — including the inbox display — on dozens of devices.

Where does the subject line cut off? Where does the preheader cut off? Are you okay with the variations across the wide array of devices you’ll be able to preview?

Catch mistakes before they go out and get seen, laughed at, or confused by your thousands of readers.

Why email open rates are only the start

Open rates matter, but a 100% open rate with a 0% click-through rate is worthless. That being said, no one clicks on an email they don’t open.

Your ultimate goals — and the metrics that matter most — pertain to sales, revenue, signups, shares, surveys filled out, and other higher-value engagement metrics.

Open rates are just the beginning. And that’s why the rest of your email has to achieve much more than deliver on the promise of the subject line. It has to engage, compel action, and meet the subscriber’s needs. It has to deliver value that the reader appreciates enough to read your future emails as well.

That’s also why you need to know that the emails you’re sending look perfect on every possible device and that everything within them works.

Email on Acid’s Email Analytics allow you to do things like:

  • Set engagement thresholds for meaningful metrics, like how long people spend reading your emails after they open them.
  • Distinguish data for different types of emails, by separating transactional emails from newsletters.
  • Use heatmapping to see how readers engage with your email content and CTAs.
  • See which devices your audience seems to prefer
  • And much more.

Take our pre-deployment platform for a spin with a free trial and discover how it feels to deliver email perfection!

Go beyond open rates: Optimize everything!

Colleagues discuss email marketing optimization.

See the results of an industry survey and find out how best-in-class marketers approach email optimization. Plus, get expert insights and unique perspectives from the Email on Acid team.

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Author: Laura Horkey

As Email on Acid’s email marketing specialist, Laura is slightly obsessed with email strategy and is often geeking out on A/B testing, behavioral patterns of subscribers, and the occasional pop culture reference in email copy. Outside of work, she can be found on a baseball field or at a backyard bonfire with her husband, two kids, and poodle-mix puppers somewhere in Northwest Arkansas.

Author: Laura Horkey

As Email on Acid’s email marketing specialist, Laura is slightly obsessed with email strategy and is often geeking out on A/B testing, behavioral patterns of subscribers, and the occasional pop culture reference in email copy. Outside of work, she can be found on a baseball field or at a backyard bonfire with her husband, two kids, and poodle-mix puppers somewhere in Northwest Arkansas.

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