What Are Open Rates and Why Are They Important?

What Are Open Rates and Why Are They Important? A woman opens an envelope.

For people using email as a marketing tool, there seems to be a lot of focus on open rates. For some people, it’s THE metric they focus on. But open rates are a small part of the email marketing metric picture and they’re not that accurate.

In this article, I take a deep dive into open rates and why you should and shouldn’t focus on the numbers.

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    What is open rate?

    In email marketing, open rate measures the percentage of subscribers who are known to have opened an email. I say known because some email clients can block the tracking of an email open. More about that later.

    It can be measured for an individual email or for all email campaigns. There are many factors that influence the open rate, but the subject line is considered one of the key influences. Having said that, it can be a misleading metric.

    It can be measured for an individual email or for all email campaigns. There are many factors that influence the open rate, but the subject line is considered one of the key influences. Having said that, it can be a misleading metric.

    To calculate open rate, subtract the number of emails that bounced from the total number of emails sent. This is the number of emails delivered. Then, divide the number of emails that were known to have been opened by that number. Multiply by 100 to get a percentage.

    Formula for calculating open rate.

    For example, imagine 1,000 emails were sent. 100 of those bounced. That’s 900 emails delivered. 500 emails were opened. 500 divided by 900 is 5.55. Multiple that number by 100 to get a percentage. The open rate is 55.55 per cent.

    How are open rates tracked?

    There are two ways to determine if an email was opened. Both rely on the email being sent in HTML format.

    HTML emails have coloured text, clickable links, images and other visual elements.

    The first involves using a tiny, invisible image called a tracking pixel. 

    When an email is opened, that image is downloaded. The email marketing service notices this and counts that as an open.

    The other method is by tracking the links in the email.

    When a recipient selects a link, it’s implied that the email has been opened because it had to have been opened for the link to be clicked.

    If the pixel is downloaded and a link clicked, it’s counted a one open. Known as a unique open.

    Why open rates are inaccurate

    The reasons open rates are inaccurate is related directly to how open rates are tracked.

    First, the tracking pixel.

    Email clients such as Gmail and Yahoo Mail have images disabled by default. Some recipients will choose to disable images only showing them for certain emails. If images are disabled, the tracking pixel isn’t downloaded. And if it’s not downloaded, the assumption will be that the wasn’t opened.

    But the tracking pixel may be downloaded more than once and not by the recipient.

    Most emails pass through some type of spam filter before being delivered to an inbox. A spam filter may download all images to validate the source and that images comply with corporate email rules. An email can be blocked if images don’t meet the corporate anti-spam rules. For instance, the image is possibly pornographic.

    Because the spam filter downloaded all image, including the tracking pixel, the email is determined to have been opened. A recipient may have opened the email and displayed images but the tracking pixel may not have been downloaded.

    If an email is too large, usually more than 102 kilobytes in size, only the first part of the email will be displayed. The email is said to have been clipped. Most tracking pixels are at the end of the email and so when an email is clipped, the tracking pixels may not be downloaded. If the recipient chooses to view the entire email, then the pixel will be downloaded and an open recorded.

    The other reason for open rate inaccuracy relates to the links.

    You may recall that if a recipient clicks a link, it’s implied that the email has been opened. Spam filters will follow links in emails to ensure the destination is safe for the recipient. Email marketing services only know the link was followed and counts this as an open.

    Then there’s Apple’s Mail Privacy Protection or MPP.

    When an Apple user elects to use Mail Privacy Protection, all of their email content is downloaded and stored on Apple’s servers. This means that all emails sent to Apple users with MPP enabled will show as being opened.

    If the recipient opens the email in their email client, the tracking pixel may be downloaded but it’s downloaded from Apple’s servers. Not the email marketing service.

    MPP only impacts the open rates determined by the tracking pixel. It does not impact link clicking.

    Why are open rates important?

    There are three main reasons email open rates are important.

    The first is that if your recipients aren’t opening emails, they’re not engaging with your business and they’re not taking the actions you want them to take. They’re not moving along your sales funnel. Each subscriber has a cost. You know, that call to action that keeps them engaged, gives them high perceived value, click links to posts, get discount codes and many other calls to action.

    Another reason is that if your recipients are not opening your emails, they’re one small step away from unsubscribing.

    The third reason, and possibly most important of the three is when recipients  don’t open emails, services such as Gmail, Outlook.com, interpret that as you’re not delivering anything of interest. This will make it increasingly likely that you’re sending spam.

    What is a "good" open rate?

    The best open rate is 100%, which is difficult to achieve. The average open rate depends on factors such as the industry in which you operate, geographic location, and audience.

    Across most industries, regardless of size, a good open rate is around a minimum of 22%.

    A good source of information for specific industries can be found at Mailchimp or Campaign Monitor.

    Geographic location can also determine a ‘good’ open rate. For instance, in Western cultures, open rates for business emails are typically very low on a Sunday. In Eastern cultures, this isn’t the case because Sunday is a normal working day.

    GetResponse collated information comparing open rates across all industries in different continents.

    (Source: Getresponse)

    Open rates for emails sent to consumers (B2C)  will vary compared to open rates that emails sent to business (B2B). For instance, business emails will have low open rates on weekends. But, if the recipient is senior management, open rates may be similar to emails sent on weekdays.

    Personal interest topics such as hobbies, have higher average open rates compared to emails relating to product sales.

    When to measure open rates

    There’s a lot written about what open rates are and how to improve the numbers, but little written about when to measure this metric.

    If you get your timing right, about a quarter of your emails will be opened within an hour of arriving in the inbox. Most emails should be opened within 24 hours. The chances of an email being opened after 24 hours are almost zero.

    When to measure does depend on the time the email was sent. If you’re sending emails based on your time zone, measure the open rate after 24 hours. If you’re sending an email to arrive based on the recipient’s time zone, measure open rates 24 hours after the last email was sent.

    How to measure an open rate

    Despite the fact that they’re inaccurate, open rates are an important metric. They should be measured and the results recorded.

    Have you heard of television ratings? This is where a subset of viewers record what programs they watch. Imagine that 100,000 viewers are involved. At 7 am on Tuesday, if 50% of those viewers are watching a specific television program, it will be assumed that 50% of all television viewers watched that same program.

    It takes into account the herd mentality.

    Tracking open rates is the same.

    If an email campaign was sent and the open rate was 20%, it’s safe to assume that 20% of all recipients opened the email even if they’re Apple users with MPP enabled.

    For instance, don’t obsess that Fred didn’t open the email because Fred may have opened it but has MPP enabled. What we should care about is that 20% of all recipients opened the email.

    Like all email marketing metrics, open rates will vary from one email campaign to the next. There are many reasons this will happen. It may have been a school holidays or a local public holiday. Track the trends. Over time, are the results trending up or down? If the result suddenly drops, investigate the reason. Severe problems will be reflected in other metrics such as bounce or spam rates.

    As to viewing open rates in email marketing services, below are some basic instructions.

    How to measure open rates in ActiveCampaign

    For campaigns

    From the left menu, select Campaigns.

    To the right of the campaign, select View Report.

    The open rate is list in the Summary panel.

    For automation emails

    Open the automation.

    For the email you want to measure, select View Report.

    The open rate is list in the Summary panel.

    How to measure open rates in Mailchimp

    In the top row, select Campaigns the Reports from the dropdown.

    To the right of the campaign, select View Report.

    In the Campaign benchmarking section, you’ll see the Open Rate.

    How to measure open rates in Klaviyo

    In the left hand menu, select Campaigns.

    The open rate for each campaign is shown on the right.

    How to improve your open rates

    Improving your open rate is as much about avoiding mistakes as doing the right things.


    If you send 1,000 emails and only 10% of those make it to the inbox, this will have a negative impact on your open rate. Only 100 people will see you email in their inbox. If 22 of these people open your email, that not a 22% open rate, that’s a 2.2% open rate.

    They key here is to make sure as many emails make it to the inbox as possible.

    From address

    You to build trust. Part of building that trust is what they see in the from address. For example, for me, you see Shane from Atomic Automation. You know it’s from me and the business I work in. Think about those from email address that say no-reply. Hardly enticing you to open them.

    Subject line

    Once your email lands in an inbox, you need to get it opened. The subject line plays an important role here. Some tactics include:


    Personalisation starts at but isn’t limited to using the recipient’s first name. You can also personalise based on the ideal open time, previous products purchased, visits to specific web pages and a lot more. You can also use words or phrases that they can relate to. Words that will increase email opens include:

    Avoid spam words

    Even if an email makes it past the spam filters, there are words and phrases that will encourage the delete option rather than the open. Words or phrases such as:

    Pre-header text

    This is the text you see next to the subject line in email clients such as Gmail and Outlook. Think of it as expanding on the subject line but not relying on the message content to attract the open. If there’s no pre-header text, the client will use text from the email content. Have a minimum of 35 characters up to around 100 characters in the pre-header text of your email.

    Consider the small screen

    Subject lines and preheader text display different on smaller screens. Some mobile clients show fewer subject line and more preheader text characters. Always test these on small screen devices.

    Clean out your list

    Cleaning your list of recipients who are never opening your emails or otherwise engaging with your business is a great tactic to increase your open rate. If you’re not sending people who aren’t engaging with your business, they can’t influence the numbers.

    Segment your list

    Sending emails that are relevant to the recipients will increase the chances of your emails being opened. If you’re a web developer and your sending emails promoting your design service to people who have already used you, they won’t open your emails and will probably unsubscribe. But, if you sent emails to those people on how they should maintain their site, or how recent events can affect the speed, it’s still of value and they’ll either advocate for your business or use you again in the future.

    Wrap up

    You can see that while it’s important to measure and track your key email marketing metrics, there can be few things to consider for some of them. With open rates, it’s helpful to understand how this metric can be affected by disengaged recipients and that a low open rate isn’t necessarily a bad thing.

    Would you like to share your open rate success? Do you need help to improve your open rate?

    Head over to the Atomic Education Facebook page and join the conversation.

    Inbox Insights: Weekly email marketing tips, blog post and course updates delivered to your inbox. Sign me up.
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