Discover how to write effective internal email subject lines that boost open rates and employee engagement. Learn best practices, common mistakes, and explore examples.
Start driving better results. Download your free internal email CTR guide now!
Access NowIn a world where employees are flooded with constant messages, internal email subject lines are often the deciding factor for whether emails are opened or ignored. Unlike external marketing emails, internal communications carry crucial information that directly impacts employee productivity and engagement. These include company updates, HR reminders, and policy changes. That’s why writing subject lines isn’t just about creativity. It’s about strategy.
A clear, compelling subject line ensures your message reaches its audience and delivers value.
According to Khalid Saleh, CEO and co-founder of Invesp and the author of a book on Conversion Optimization, 47% of email recipients open email based solely on the subject line. On the other hand, 69% of email recipients report email as spam based on the subject line. But then, strangely, emails with no subject at all have an open rate of 8% more than those with a subject line, whereas emails with personalized subject lines are 22% more likely to be opened. He also maintains that if the word “newsletter” is used in subject lines, the open rate decreases by 18.7%, while using the word “free” in the subject line results in a 10% increase.
Saleh also ranks open rates in accordance with the number of words in an email subject line:
So, how can you rectify this and ensure your subject lines actually work for you rather than against you? The answer lies in understanding why subject lines are so crucial in internal communications, and how they shape employee behavior right from the inbox.
The subject line of an email message is the first impression of your message. Before employees ever click to read, they form a judgment about whether the content is worth their time based on those few words. A vague or uninspired subject line risks burying your email in a crowded inbox.
Internal email subject lines for newsletters and all types of messages also directly impact open rates and engagement. Just like in external marketing, higher open rates for internal emails mean your updates are reaching and resonating with employees. The right subject line can spark curiosity, highlight urgency, or clearly state the value of the message inside.
Also, subject lines help employees prioritize important updates. In busy inboxes where hundreds of messages compete for attention, a concise, well-crafted subject line signals which communications are critical. This allows employees to focus on what matters most. Whether it’s a security alert, a benefits deadline, or a company-wide announcement, a compelling subject line will ensure employees don’t miss vital information.
As a University of Minnesota Marketing Communications post states, email is often a critical part of most communication plans.
“While the majority of a communicator’s time might be spent writing the email’s body copy, remember that the subject line is the first — and sometimes only — thing your audience will see. A strategic subject line can determine whether an email is opened, which can help reach your internal communications goals.”
University of Minnesota Marketing Communications
Getting internal email subject lines right is both an art and a science. Employees receive dozens, sometimes hundreds, of internal messages every week. Without a clear strategy, your updates risk being buried in crowded inboxes or dismissed as irrelevant. Strong subject lines not only grab attention but also help employees understand what to expect before they click.
Here are six proven practices that will help you elevate your subject lines and ensure your communications get the engagement they deserve.
Aim for 6–10 words (Khalid Saleh’s top choice) or 40–50 characters to ensure your internal email subject lines are scannable across desktop and mobile devices. If they aren’t, you will find that long or wordy subjects will often be cut off, leaving employees unsure of what the message is about. It also helps to front-load key information by placing the most important information at the beginning of the subject line. The goal is to make the core message instantly obvious so readers don’t waste time guessing.
Examples:
Avoid generic lines like “Important Update” or “Company News.” These internal email subject lines lack context and fail to convey urgency or value. Instead, tie the subject line directly to the email content. It is especially important for event invites, HR updates, or upcoming deadlines. Specificity builds trust, signaling that the email contains meaningful information worth their attention.
Example: Training Registration Closes Friday
Internal email subject lines with strong verbs encourage employees to engage and take the next step. Action-oriented phrasing transforms a passive update into a call to action, making it clear what’s expected. This technique is especially effective for tasks with deadlines, like surveys or benefits enrollment.
Example: Action Required: Complete Your Benefits Enrollment Today
Not every subject line needs personalization, but tailoring these by team name, department, or location can significantly increase relevance. Employees are more likely to open messages that feel directed at their role rather than a generic blast. This also helps reduce the sense of email overload because recipients feel the content applies to them specifically.
Example: Marketing Team: Share Your Q4 Campaign Ideas
Used strategically and sparingly, emojis can help internal email subject lines stand out in crowded inboxes. They add warmth and personality, making cultural or celebratory announcements more inviting. However, overuse can feel unprofessional or distracting, so emojis should only be included when the context fits and the tone is appropriate. Also, as the Minnesota University Marketing Communications post warns, while most users can view emojis, screen readers may not interpret them accurately. Their advice is to use emojis alongside clear text for context — or don’t use them at all.
Example: 🎉Don’t Miss This Friday’s Team Celebration
Your subject line should mirror the weight of your message. For instance, compliance notices, policy changes, or legal updates require a straightforward, formal tone to signal seriousness. By contrast, cultural updates, wellness reminders, or celebration announcements benefit from a more conversational style. Matching tone with context ensures employees immediately understand both the nature and importance of the communication.
Examples:
Even the best communicators can fall into subject line traps that reduce open rates or erode trust over time. Avoiding these pitfalls is just as important as following best practices. Here are three common missteps we suggest you steer clear of.
When every email is marked “urgent” or “important,” employees quickly learn to ignore the label. Overusing these terms not only dilutes credibility but can also cause people to overlook truly critical updates. Reserve urgency for situations where immediate action is required, such as system outages or compliance deadlines.
A subject line that says simply “Update” or “FYI” offers no context, leaving employees uncertain about whether the email matters to them. On the other hand, subject lines that run too long get cut off visually, especially on mobile devices, causing important details to be lost. Aim for clarity and brevity so employees immediately know what to expect.
Phrases like “You Won’t Believe This!” or “Game-Changing News Inside” may grab attention externally, but inside the workplace, they often feel inauthentic and misleading. Employees want transparency and efficiency, not gimmicks. Subject lines should build trust and respect employees’ time rather than mimic marketing tactics.
Examples are often the best way to spark inspiration. Subject lines will vary depending on the type of internal message, but the goal remains the same: clarity, relevance, and engagement. Below are sample subject lines grouped by common communication categories:
Subject lines for company announcements should highlight the scope and importance of the news clearly. Focus on transparency and making it easy for employees to quickly understand what the announcement means for them.
Examples:
HR and compliance messages need to be clear, professional, and deadline-driven. Subject lines should signal urgency when required while avoiding alarmist language.
Examples:
Event-related subject lines should drive participation by emphasizing timing, relevance, or the value (or fun) of attending. Make registration deadlines or key details instantly visible.
Examples:
Culture-building subject lines should feel warm, positive, and inclusive. Use them to celebrate people, achievements, and shared experiences across the organization.
Examples:
Internal email subject lines for IT and computer system alerts must be straightforward and action-focused. Employees should immediately know if a system issue, maintenance window, or action (like resetting passwords) affects them.
Examples:
Wellness-focused subject lines should be supportive, approachable, and inviting. Highlight resources and opportunities that encourage employees to prioritize their health and well-being.
Examples:
Project-related subject lines should spotlight progress, milestones, or new resources. Keep them concise and focused on outcomes employees care about.
Examples:
Leadership subject lines should convey authority and authenticity. Make it clear when the message comes directly from an executive or manager to signal importance.
Examples:
Survey subject lines need to be engaging and action-oriented. Use them to make participation feel valuable and easy, emphasizing that employee input really matters.
Examples:
These subject lines should be lighthearted, fun, and inclusive. Use them to build excitement and encourage participation in company-wide celebrations or informal events.
Examples:
You can, of course, also send a personalized birthday message to individual employees.
Crafting subject lines doesn’t have to be guesswork. Cerkl Broadcast equips internal communicators with features that make subject lines more effective, personalized, and engaging, without adding extra effort.
Personalization fields let you automatically insert employee names, departments, locations, and much more into subject lines. This approach instantly makes messages feel more relevant and tailored to the reader’s role. Instead of generic announcements, each employee sees a subject line that speaks directly to them, which boosts open rates and reduces “email fatigue.”
The way it works is that you add the personalization field to your email subject line, and the system pulls individualized information from each subscriber profile.
You can also add personalization fields to text elements, adding many personalization fields to each Email Blast. And you can use each one multiple times — for example, by repeating the employee’s name within the email text.
If there is missing data in an employee’s profile information, you will receive a warning so that you can update the relevant fields.
Broadcast also enables you to use emojis in email subject lines, as well as in titles and in the elements of an email. Because screen readers may not interpret emojis accurately, and because they are rendered differently according to different devices and email clients, we advise users to send themselves a sample to check how recipients will view them.
Of course, there’s a lot more to successful emails than just having the best internal email subject lines. Our free guide, Best Practices and Proven Strategies to Improve Email Click-Through Rates, highlights that high email click-through rates (CTRs) are crucial for employee engagement and productivity. We cover email metrics, AI security scanning tools, and consider how good email CTR enhances internal comms. We also consider seven email best practices that will help you boost CTR. It shouldn’t come as a surprise that at the top of this list is how to craft engaging subject lines!
Don’t miss this opportunity. Want to dive deeper into boosting your open and click rates? Download our free resource now.
What is a good subject line for an email? A good subject line is short, clear, and directly tied to the content of the message. It gives recipients an immediate reason to open the email by highlighting value, urgency, or relevance.
What are some creative subject line ideas? Creative subject lines often use personalization, light humor, or emojis to grab attention while staying aligned with the message. For internal emails, this might mean celebrating milestones, asking a playful question, or adding a timely cultural reference.
What internal email subject lines get the most opens? Subject lines that are specific, action-oriented, and relevant to the recipient’s role or needs typically see the highest open rates. Personalization and concise phrasing also play a big role in encouraging clicks.
Revolutionize your internal comms with minimum effort.
All Cerkl products are 100% built (and supported) with ❤️ in Cincinnati, Ohio, USA.
Copyright 2025, all rights reserved.
Want to boost employee engagement by at least another 23%? This white paper reveals the proven pathway to supercharge your internal communications and unlock the secrets to powerful, lasting employee engagement.
Claim your free copy now!
