Email is the most popular communication channel. So, it’s vital to track email metrics, especially internal email open rates. Here’s why and how.

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As the accessibility of the Internet continues to increase year after year, so does the number of emails sent and received globally. In 2017, Statista estimated the global figure to be 269 billion. Last year (2024), this figure had increased to 361.6 billion — and by 2027 it’s expected to hit 408.2 billion. Predictably, it’s becoming increasingly difficult to capture employees’ attention with corporate emails. This means that as an internal communicator, you need to implement tactics that make your employees excited to receive their organizational newsletters and team messages sent via email.
Adding to this challenge, Gallagher’s definitive State of the Sector 2024/25 survey found that email was the most divisive channel when it comes to listening strategies for employees. According to the company’s 2025 Employee Communications Report, one in three internal communicators say their organization doesn’t have a listening strategy or plan documented — but they agree it’s an integral part of their everyday role.
At the same time, 31% of communicators regard a listening strategy as one of their top three functions when evaluating the purpose of comms. However, when asked to rank the value of email as a listening method, only 25% said it was valuable, 46% ranked it as moderately valuable, and 29% said it generated low-value feedback.
Nevertheless, when it comes to channel effectiveness, Gallagher found that email still ranks high on the list both in terms of usage and efficacy. For example:

Email open rates (ORs) and click-through rates (CTRs) are two relatively easy email metrics we use to measure the effectiveness of email marketing campaigns. They are also the most popular key performance indicators (KPIs) used to track whether an internal communications strategy is working. Click-to-open rates (CTORs) are another widely used metric, often included in corporate reporting.
Email remains a cornerstone of corporate communication, with internal communicators regularly sending a significant number of email broadcasts to keep employees informed and engaged. However, ensuring these messages are both opened and read requires careful attention to KPIs.
But what do these metrics represent and why are they critical?
By focusing on these benchmarks, internal communicators can gain insights into how their email campaigns perform and identify areas for improvement. After all, tracking metrics is the first step to managing and optimizing internal communications effectively, and the ease of measuring these rates varies, depending on the email marketing platform or tool you’re using.
The email click-through rate for internal emails measures the percentage of employees who click on a link within the email. If you send 100 emails, and 5 recipients click on a link, the CTR will be 5% → (Number of clicks / Total emails delivered) x 100.
Industry benchmarks suggest that click-through rates for internal emails can vary widely across organizations and industries. While some companies report rates as low as 1%, others achieve rates exceeding 50%, depending on factors such as content relevance, clarity of the call to action, and audience segmentation. On average, a CTR of around 7% to 10% is considered reasonable for internal communications. Tracking this metric helps organizations determine whether their content is resonating with employees and driving engagement.
The email open rate for internal emails is also known as a unique open rate (UOR). It measures the percentage of employees who open their internal email. If you send 100 emails, and 30 recipients open the email, the open rate is 30% — (Number of opens / Total emails delivered) x 100.
ORs for internal emails typically vary based on factors such as subject line appeal, timing, and the perceived value of the message. Studies suggest that ORs in most industries range from 40% to 85%, with some organizations achieving even higher rates through targeted and personalized communication strategies. Monitoring this metric helps gauge the initial reach of your email campaigns and serves as a baseline for assessing engagement.
The click-to-open rate for internal emails measures the percentage of employees who click on a link within an internal email after opening it. This metric helps you understand how engaged your audience is with your content. For example, If you send 100 emails and 30 people open the email AND 10 click on the link, the CTO will be 33.3% (10/30) — (Number of clicks / Number of opens) x 100.
It’s crucial to differentiate between CTRs and CTORs because these metrics provide distinct insights into your email marketing campaign’s performance. While both measure the percentage of recipients who click on links within emails, CTORs focus on the effectiveness of your content with your engaged audience. CTRs, on the other hand, indicate the general engagement of your total audience. CTORs help you understand how well your email content resonates with your audience. CTRs help you identify what percentage of your audience cares about your content.
Conversion rates measure the percentage of recipients who took a desired action, such as making a purchase, filling out a form, or subscribing to a newsletter. This metric helps you understand the effectiveness of your email marketing campaigns in driving desired actions. When you are assessing the conversion rate, the formula is (Number of conversions/ Number of recipients) x 100. So, if you sent 100 emails and 20 recipients converted them by, for instance, buying something, the conversion rate would be 20%.
The engagement over time (EOT) rate measures the percentage of recipients who engage with your email over a specific period of time. This metric helps you understand how well your email marketing campaigns are resonating with your audience over time.
The formula for this is (Number of engaged recipients / Total recipients) x 100. So, if you sent 100 emails and 30 recipients engaged with the email (e.g. opened, clicked, or converted) over a two-week period, the EOT rate would be 30%.
The unsubscribe rate measures the percentage of recipients who opted out of receiving future emails. This metric helps you understand how well your email marketing campaigns are resonating with your audience and identify potential issues that may lead to unsubscribes. So, if you sent 100 emails and 5 recipients unsubscribed, the unsubscribe rate would be 5%. (Number of unsubscribes / Total recipients) x 100.
If employees are unsubscribing from corporate emails, you need to take action and find out why. High unsubscribe rates may signal that your content isn’t relevant, timely, or personalized enough. Review email frequency, messaging tone, and segmentation strategy to realign with employee needs and preferences.

Internal email open rates can vary depending on several factors, such as the purpose of the email, the audience, and the content.
Research from industry sources suggests that ORs for internal communications often fall between 60% and 80%, with variations depending on organizational size and employee engagement levels. For comparison, average ORs for external business emails are significantly lower, typically around 20% to 25%.

A Forbes Advisor post by Katherine Haan, 49 Top Email Marketing Statistics, that was audited and verified in 2024, states that the average open rate for email marketing campaigns is 36.5%.
Cerkl Broadcast has been used to deliver more than 100 million Email Blasts to inboxes. While delivery rates have ranged from 98.08% to 100%, open rates have been variable over time — reaching highs of 82.35% and 95.38%, and averaging 46.56%.
These differences highlight the unique nature of internal communications. Employees are more likely to engage with emails directly related to their work, benefits, or organizational updates. However, while open rates are a useful metric for gauging initial engagement, they don’t always correlate directly with CTRs.
But why are open rates and click-through rates so different? While delivery rates have ranged from 98.08% to 100%, open rates have been variable over time, ranging from as little as 12.01% to 95.38%, and averaging 46.56%.
The disparity between internal email ORs and CTRs can be attributed to several factors. While open rates might be high, translating these openings into meaningful actions (clicks) requires clear and compelling content. Here are a few possible reasons for the differences.
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Despite the challenges and stumbling blocks, there are many ways you can improve your internal email open rates and CTR. Some of these are surprisingly simple, requiring careful thought rather than high-tech knowledge.
It can be easy to make your subject line the key takeaway of the communication you’re sending. However, unless you are careful, that can make for a pretty uninviting email. Try putting yourself in the recipient’s shoes and have the subject line answer the question, “What’s the benefit employees will get if they read this email?” Rather than saying, “New Volunteer Opportunities,” opt for something like, “Give back to our Chicago community and save lives.”
One thing that we have found very successful with our Cerkl clients is the use of personalized subject lines. When employees know they are receiving content just for them, they’re more likely to open their internal emails.
The Forbes Advisor post confirms the importance of personalization.
“Personalized emails are significantly more effective at capturing recipients’ attention. By tailoring content to individual preferences and behaviors, marketers can achieve a 26% higher open rate. This approach ensures that emails are more relevant and engaging, leading to better results.”
Katherine Haan
Your corporate news shouldn’t read like a press release. That’s not what it is. Sometimes company language can get stuffy and annoying, especially if your employees are using the same jargon day in and day out.
Instead, try to become the virtual water cooler of the office. Yes, there are imperative legal and benefit updates that you still have to send out. But creating spotlights and testing with different types of content will be a lot more likely to make employees excited to see your email pop up in their inboxes.
A huge number of employees globally are using their mobile devices to check messages. While a common estimate is that mobile email accounts for anything from 26% to 78% of email opens, depending on your target audience, product, and email type, the Forbes Advisor post pegs the figure for marketing emails at 41%. The rest of email views amount to 39% on desktop computers and 20% on tablets and other devices. This is why it’s so important to ensure emails are accessible and engaging across all devices.
Until relatively recently, most emails were designed primarily for desktop viewing, often overlooking the mobile experience. When your employees view their inbox on their smartphones, most email platforms surface the first few lines of an email or designated alternate text. Make sure you don’t waste this opportunity and define your preview text to make your employee newsletter more compelling.
Determining the best time to send internal emails can be challenging, as employee preferences and schedules vary widely. Research from multiple non-competitive sources suggests that the most effective times often align with lower inbox competition. Early weekday mornings and Sundays are frequently cited as optimal because employees tend to have fewer distractions and more time to engage with messages during these periods.
For example, studies have shown that emails sent between 6 am and 9 am on weekdays often achieve higher open rates, as they catch employees at the start of their day. Similarly, Sunday afternoons can be an effective time, as many employees begin to mentally prepare for the upcoming week, reviewing emails and schedules.
To further enhance engagement, consider allowing employees to personalize their email delivery preferences. By giving employees the ability to choose their preferred time and frequency for receiving internal communications, you ensure a more tailored and non-intrusive experience while still achieving your organizational goals.
Send emails to the audience that needs it. Not every employee needs to know that your downtown location is having elevator service issues, but you’ll want to tip off the employees in that location who don’t want to walk up 12 flights of stairs.
Our clients love our Audience Manager feature for making sure that the right audience is getting the right message.
Internal email retargeting is a modified marketing strategy that involves sending targeted emails to users who have previously interacted with your brand but have not yet converted or taken a desired action. This approach is also known as ‘retargeting’ or ‘remarketing’.
For internal communications, this approach is a great way to follow-up with employees who have not yet completed a desired action, such as signing up for a newsletter or downloading a resource. By sending targeted emails, you can reignite their interest and encourage them to take the desired action.

The platform you choose to use really does make a difference. Cerkl Broadcast can help with:
Maddy Rieman, Head of Customer Success at Cerkl, has a whole lot more Tips for Increasing Your Open Rate. Don’t miss them!

Despite the challenges and stumbling blocks, there are many ways you can improve your internal email open rates and CTR. Some of these are surprisingly simple, requiring careful thought rather than high-tech knowledge.
It can be easy to make your subject line the key takeaway of the communication you’re sending. However, unless you are careful, that can make for a pretty uninviting email. Try putting yourself in the recipient’s shoes and have the subject line answer the question, “What’s the benefit employees will get if they read this email?” Rather than saying, “New Volunteer Opportunities,” opt for something like, “Give back to our Chicago community and save lives.”
One thing that we have found very successful with our Cerkl clients is the use of personalized subject lines. When employees know they are receiving content just for them, they’re more likely to open their internal emails.
The Forbes Advisor post confirms the importance of personalization.
“Personalized emails are significantly more effective at capturing recipients’ attention. By tailoring content to individual preferences and behaviors, marketers can achieve a 26% higher open rate. This approach ensures that emails are more relevant and engaging, leading to better results.”
Katherine Haan
Your corporate news shouldn’t read like a press release. That’s not what it is. Sometimes company language can get stuffy and annoying, especially if your employees are using the same jargon day in and day out.
Instead, try to become the virtual water cooler of the office. Yes, there are imperative legal and benefit updates that you still have to send out. But creating spotlights and testing with different types of content will be a lot more likely to make employees excited to see your email pop up in their inboxes.
A huge number of employees globally are using their mobile devices to check messages. While a common estimate is that mobile email accounts for anything from 26% to 78% of email opens, depending on your target audience, product, and email type, the Forbes Advisor post pegs the figure for marketing emails at 41%. The rest of email views amount to 39% on desktop computers and 20% on tablets and other devices. This is why it’s so important to ensure emails are accessible and engaging across all devices.
Until relatively recently, most emails were designed primarily for desktop viewing, often overlooking the mobile experience. When your employees view their inbox on their smartphones, most email platforms surface the first few lines of an email or designated alternate text. Make sure you don’t waste this opportunity and define your preview text to make your employee newsletter more compelling.
Determining the best time to send internal emails can be challenging, as employee preferences and schedules vary widely. Research from multiple non-competitive sources suggests that the most effective times often align with lower inbox competition. Early weekday mornings and Sundays are frequently cited as optimal because employees tend to have fewer distractions and more time to engage with messages during these periods.
For example, studies have shown that emails sent between 6 am and 9 am on weekdays often achieve higher open rates, as they catch employees at the start of their day. Similarly, Sunday afternoons can be an effective time, as many employees begin to mentally prepare for the upcoming week, reviewing emails and schedules.
To further enhance engagement, consider allowing employees to personalize their email delivery preferences. By giving employees the ability to choose their preferred time and frequency for receiving internal communications, you ensure a more tailored and non-intrusive experience while still achieving your organizational goals.
Send emails to the audience that needs it. Not every employee needs to know that your downtown location is having elevator service issues, but you’ll want to tip off the employees in that location who don’t want to walk up 12 flights of stairs.
Our clients love our Audience Manager feature for making sure that the right audience is getting the right message.
Internal email retargeting is a modified marketing strategy that involves sending targeted emails to users who have previously interacted with your brand but have not yet converted or taken a desired action. This approach is also known as ‘retargeting’ or ‘remarketing’.
For internal communications, this approach is a great way to follow-up with employees who have not yet completed a desired action, such as signing up for a newsletter or downloading a resource. By sending targeted emails, you can reignite their interest and encourage them to take the desired action.

The platform you choose to use really does make a difference. Cerkl Broadcast can help with:
Maddy Rieman, Head of Customer Success at Cerkl, has a whole lot more Tips for Increasing Your Open Rate. Don’t miss them!

We’ve made it easy for you to maximize your internal email open rates. All you need is our free internal communication email template. Download it now.

What is a good open rate for email? A good open rate for email is typically considered to be around 20-30%, although this can vary depending on the industry, audience, and content.
What are the benchmarks for internal email communications? For internal email communications, internal email benchmarks can vary depending on the organization and audience. However, a good starting point is to aim for an open rate of 30-50% and a click-through rate of 5-10%.
What is the best time to send an internal email? The best time to send an internal email is debated often. Some say it’s a good idea to send emails during working hours when most employees are likely to be at their desks. Others say you should send them on Sundays or early on Monday mornings.
How do I increase my internal newsletter readership? To increase internal newsletter readership, try to make the content relevant and engaging. Use attention-grabbing subject lines, and consider segmenting your audience based on interests or departments.

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