21 Email Mistakes That Are Costing You Time, Credibility, and Results — And How to Fix Them
Let’s face it, email is broken. Most of us are actually making an email mistake or two on a daily basis.
We send too many. We read too few. And most of them? They’re a mess.
Inboxes are war zones. You’re dodging CCs, deciphering vague subject lines, and wondering what on earth “What are your thoughts?” even means.
But here’s the kicker: email isn’t going anywhere. So if you want to stand out, get replies, and stop irritating your colleagues, it’s time to fix your email game.
We’ve analysed thousands of emails (and yes, we’ve made these mistakes too). Here are the 21 most common email mistakes and how to write emails that actually get you what you want.
What Does a ‘Bad’ Email Look Like?
To: Joe; Jenny; Ian; Phil; Collin;
Subject: Pack size
Cc: Marie; Jack; Sean; Eve; Eric; Steve; Ben; Lucy; Tom; Mark;
“Hi
Hope your are ok
I’m ‘fraid the pack size is a problem for the factory and they need more
stores for the cost. Iam trying to persuade the factorey. This week has been a tough week because of the visit and Marks’ comments so we’ll STRUGGLE – the question you asked last week about the project yeah I like it.
Plesae let me know your thoughts ASAP and the data I asked for 2 weeks ago!. Best.”
The Mistakes Made in this Email are Identified Below:
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21 Email Mistakes You Can Fix Today:
Each email mistake has a graphic outlining the facts, future, form, and feelings of each mistake, based on their being 4 types of people, according to the HBDI psychometric test.

Email Mistake 1. Too Many People in the ‘To’ Field
When everyone’s responsible, no one is.
Fix: Only include people who need to act. Use ‘To’ for action, ‘CC’ for info.

If you are struggling to understand the 4 boxes, the thinking preferences, I suggest focusing on one box, maybe the green box, because this is the next step box. If you’re good with the thinking preferences, fabulous. Well done. HBDI is a great tool to help you understand how you prefer to think.
Email Mistake 2. Overusing ‘CC’
Also known as “arse-covering.”
Fix: Ask yourself: Does this person really need to see this? If not, leave them out.

Email Mistake 3. Vague Subject Lines
“Cheese” is not a subject line
Fix: Be specific. Try: “XYZ Pack Size – Reply by Thursday, 5pm”. Aim for 65 characters max.

Email Mistake 4. No Call to Action
If you don’t ask, you don’t get.
Fix: End with a clear ask and a deadline. “Please confirm by Friday, 2pm.”

Email Mistake 5. Unclear Purpose
What do you want me to do?
Fix: Start with the end in mind. Make your ask obvious in the first few lines.
Email Fact 1:
The average person spends 11.1 seconds reading an email.

Email Mistake 6. Long and Waffling
Nobody has time for your email novel.
Fix: Stick to 100–150 words. Use bullet points. Cut the fluff.

Email Mistake 7. Spelling and Grammar Errors
You’re not texting your mate.
Fix: Use spellcheck. Read it aloud. Or better yet, use Grammarly.

Email Mistake 8. Poor Email Opening
“Hope you are OK” isn’t winning hearts.
Fix: Be human. Be clear. Try: “Good morning – thanks for your help on XYZ.”

Email Mistake 9. Weak Email Closing
“Best.” What does that even mean?
Fix: End with warmth and clarity. “Thanks in advance – looking forward to your reply.”

Email Mistake 10. Missing the Next Step
If I don’t know what to do next, I’ll do nothing.
Fix: Spell it out. “If you agree, I’ll add it to the schedule.”
Email Fact 2:
Around 67% of emails are opened on a mobile device.
This reduces the visible subject line and often distorts your images or formatting.

Email Mistake 11. Adding No Value
Don’t email just to be seen
Fix: Ask: Am I helping move this forward? If not, don’t hit send.

Email Mistake 12. Formatting Overload
Fonts, colours, bold, italics — it’s a circus.
Fix: Keep it clean. Use bold sparingly. Avoid rainbow emails.

Email Mistake 13. Subject Line (Again)
Still writing “Update”?
Fix: Include the topic, action, and deadline. “ABC Project – Feedback by 3pm Wed”

Email Mistake 14. Expecting Instant Replies
Email is not WhatsApp.
Fix: If it’s urgent, call. Don’t expect a reply in 15 minutes.

Email Mistake 15. Not Asking for What You Want
Be direct. Don’t dance around it.
Fix: “Can you approve the budget by Friday?” Not “What are your thoughts?”
Email Fact 3:
The average knowledge worker spends 5.4 hours per day looking at emails, checks their emails 5 times per hour and is interrupted by an email notification over 100 times per day.
What productivity improvement would you see with more efficient emails?
Email Mistake 16. Sending at the Wrong Time
8:34pm? Really?
Fix: Send between 6am–8am for best open rates. Schedule it if needed.

Email Mistake 17. Wall of Text
If it looks like a novel, it won’t get read.
Fix: Use short paragraphs. Add white space. Break it up.

Email Mistake 18. Too Short or Too Long
One-liners confuse. Essays overwhelm.
Fix: Aim for 100–150 words. Enough to inform, not bore.

Email Mistake 19. Asking for Too Much
3 questions, 4 attachments, 5 deadlines?
Fix: Stick to one ask per email. Or use bullets if you must.

Email Mistake 20. “What Are Your Thoughts?”
It’s vague. It’s lazy. It gets ignored.
Fix: Be specific. “Do you agree with Option A or B?”
Email Fact 4:
333,000,000,000 (333 Billion) emails are sent and received every day, worldwide. With this number estimated to reach 376 billion by 2026.
Email Mistake 21. Sending Emails That Irritate Everyone
You know the ones.
Fix: Pause. Reread. Ask: Would I want to receive this?
Bonus: The Psychology Behind It All
We all think differently. That’s where HBDI comes in:
– Blues (Facts): Want data and logic.
– Yellows (Future): Love big-picture thinking.
– Reds (Feelings): Need connection and empathy.
– Greens (Form): Crave structure and clarity.
A great email speaks to all four. So mix it up — a stat, a story, a plan, and a purpose.
The Fix: One Email to Rule Them All
Here’s how the bad email from earlier could look:
To: Joe
Cc: Elaine
Subject: XYZ Pack Size – Reply by Thursday 5pm
“Good afternoon. Thanks for your help on the Better Save project.
Following up on Tuesday’s request about pack size reduction.
The factory has concerns. I explain in this short video [link].
If you can agree to list in 50 more stores, we can proceed.
Please confirm by Thursday, 5pm. If not, let’s chat Friday at 2pm.
Elaine is copied as the team meets next week.
Thanks in advance,
Eddie”
119 words. 65-character subject. Clear. Polite. Actionable.
Final Thought:
Email Isn’t Dead — But Bad Email Should Be
You don’t need to write like Shakespeare. You just need to write like someone who respects the reader’s time.
So next time you hit “New Email,” remember:
Be clear. Be kind. Be brief.
And if you want to go deeper, check out our Time Management and Executive Coaching courses.












