A panel of communications experts helped us test how well artificial intelligence tools ChatGPT, Claude, Copilot, DeepSeek and Gemini write emails. https://www.washingtonpost.com/technology/2025/03/26/best-ai-email-assistant/ (Illustration by Johanna Walderdorff for The Washington Post) 5. Microsoft Copilot 4. OpenAI’s ChatGPT 3. Google’s Gemini 2. DeepSeek 1. Anthropic’s Claude What did we learn? Review by Geoffrey A. Fowler There are lots of AI helpers out there now. But only one can write emails as well as you. To figure out which artificial intelligence assistant is worth your time and money, I set up an old-fashioned bake-off. I asked five bots to draft five kinds of difficult work and personal emails. Then I brought together a blue-ribbon panel of communications experts to judge all the emails — blind. To see whether the bot emails were distinguishable from human ones, I also had the judges score emails written by me. One hundred fifty email evaluations later, one AI did outperform this human. But the judges also thought one of the most popular AIs right now sounded so robotic, you might want to avoid it. Why focus on writing email? It’s one of the first truly useful things AI can do in your life, from dashing out quick replies to helping you find the words for a difficult conversation. AI writing tools are also now available inside Gmail and Outlook, making them as accessible as spell-check. And the skills AI demonstrates in drafting emails also apply to other kinds of writing tasks. Our judges, who have all written books and teach courses on communication, include Erica Dhawan, Carmine Gallo, Ann Handley, Shari Harley and Pamela Skillings. Skip to end of carousel How we tested the AI bots We fed these five email-writing prompts to ChatGPT, Claude, Copilot, DeepSeek and Gemini. Then our judges ranked their output. Prompt 1: An apology letter (adapted from a Carolyn Hax column) I have kids who are 8 months old and 2 years old, so when a childless friend told me she had been sleep-deprived, I just laughed and told her she doesn’t know what sleep-deprived is. She didn’t say anything about it in the moment but then later sent me an email detailing health problems she’s had related to insomnia and telling me she thought I was insensitive. I replied, “You’re acting like this is personal about you. I’m just telling you, no parent wants to hear a nonparent whine about not sleeping.” She didn’t reply to that and I had basically forgotten about it, but I saw her yesterday and she was very cold to me. Draft another email to her. Prompt 2: A CEO announcing a big layoff I’m George, the founder and CEO of a 1,000-person company named AirBuds. Draft a short email to the entire company announcing we will be laying off 35 percent of the workforce. I made a bad bet on an app redesign that drove away some loyal customers and ended up costing us millions. Employees have also lost a lot of productivity by working from home in recent years. The company will be making the cuts based on performance reviews and offering everyone impacted three weeks of severance pay. About a third of the impacted jobs the company will be replacing with AI engineers. The tone should be serious and self-effacing. Prompt 3: A difficult spousal request Write a short message to my husband, Sam, convincing him that we should move to the North Pole for a year. The tone should be funny and excited. Prompt 4: A weird work proposal Draft a short email to my company’s VP of human resources Bill to convince him that the company should convert the break room into a ball pit. Make logical arguments. The tone should be reasoned and reasonable for a corporate setting. Prompt 5: A breakup text Write a short message to a girl named Sarah I met on Hinge to tell her that I want to break up with her. I want to remain friendly but not actually be her friend. (We know a few people in common, so I might run into her from time to time.) We chatted for a few weeks and went on two in-person dates and hooked up once. She might take it kind of tough, so please be kind but firm. 1/5 End of carousel When you’re choosing a writing assistant, there may be additional factors that tip the scales for which AI to use, such as direct access to your inbox or other personal information. Here are the AI bots, ranked from worst email writing to best. 5. Microsoft Copilot Return to menu Score: 23 out of 100 Prompt 1: an apology letter Ann Handley: How this reads ... Dear friend: WHY WRITE FROM HEART WHEN AI CAN DO IT FOR U Subject: An Apology and a Clarification Dear [Friend's Name], I hope this email finds you well. I wanted to reach out because our recent conversation has been weighing on my mind, and I realize that my response to your email was hurtful. I am genuinely sorry for my insensitivity and for not fully understanding your situation. As a parent of two young children, I often find myself overwhelmed and exhausted, and I didn't take the time to appreciate that sleep deprivation and insomnia are real struggles for many people, regardless of whether they have children or not. I now understand that my comments came across as dismissive and invalidating to your experiences and health challenges, and for that, I am truly sorry. You are an important person in my life, and our friendship means a lot to me. I hope we can talk about this further and find a way to move forward. I am here to listen and better understand what you’ve been going through. Thank you for your understanding, and I hope to hear from you soon. Warm regards, [Your name] Erica Dhawan: Feels a bit formal and over-apologetic. Pamela Skillings: Okay, this is your friend. You don't need this stiff explanation. Erica Dhawan: Could use a bit more warmth to make it feel more genuine. Carmine Gallo: unnatural language Pamela Skillings: Overall, feels very stiff and soulless — very “AI”! Send Copilot, the AI assistant available in Microsoft’s Windows, Word and Outlook, is ubiquitous. But if there’s one thing our judges agreed on, it’s that Copilot writes emails that sound like AI — and they scored it dramatically lower than the other bots. Copilot began messages with some variation of super-generic “hope you’re well” on three of our five tests, which lends it a feeling of being “impersonal,” said Dhawan. Copilot being “tone-deaf” was a recurring concern of the judges. In the test email announcing layoffs, Gallo said Copilot used “stilted, robotic language.” And writing a short breakup message, Copilot ended with the phrase, “I hope we can keep things amicable.” Wondered Harley: “Why wouldn’t things be amicable? I would have picked different language.” What’s worse, Copilot was, overall, the wordiest of the AIs. In a business email, it used twice as many words to convey the same argument as ChatGPT. Copilot is available at copilot.microsoft.com and included in Microsoft 365 apps with a paid personal or family subscription. 4. OpenAI’s ChatGPT Return to menu Score: 43 out of 100 ChatGPT is the most famous of the bots, but its emails didn’t stand out much from the other two AIs in the middle of our rankings. Several judges credited ChatGPT for sounding “direct,” as opposed to jargony and cagey, in our layoff notice test. On emails that required more persuasion, Handley gave ChatGPT credit for using descriptive language to conjure up a feeling. “This isn’t my favorite writing,” she said, “but from a sales and marketing perspective, it’s the strongest because it sells the idea the best.” Yet the judges also felt ChatGPT often missed the mark by coming across “a bit stiff” and “transactional.” For example, it used the passive-aggressive phrase “that said” for a key turn in a breakup message. These sorts of cringey moments popped up frequently: The opening line of a test email to a spouse “already sounds defensive,” said Gallo. ChatGPT is available at chatgpt.com. 3. Google’s Gemini Return to menu Score: 44 out of 100 Gemini is the assistant built into Gmail. Over half of our judges could smell something was off about it from a mile away. “I don’t feel like it came from a real person,” said Gallo. “I would immediately recognize this as being written by AI and wonder why my friend couldn’t be bothered to write me a quick email from the heart,” said Skillings. But Gemini did have its moments. Its breakup message test was simple and short. “This seems to be the text that will cause the least damage,” said Gallo. And when it comes to making arguments, Dhawan said, Gemini’s email is “comprehensive and well-organized” — and even better “acknowledges potential objections and offers solutions.” Gemini is available at gemini.google.com and available directly in Gmail with a Google One subscription. 2. DeepSeek Return to menu Score: 45 out of 100 DeepSeek, made in China, overall scored a bit better than American rivals ChatGPT and Google. But most of the judges found it hard to differentiate the three of them. In business emails, DeepSeek was good at laying out reasoning. “I like the clarity of the argument,” said Gallo. “The writer shows self-awareness and acknowledges obstacles.” Handley liked DeepSeek’s language use, including alliteration and a joke in one email that, she said, “actually made me lol.” In the breakup message, Handley said the way it presented the news was “honest and real.” DeepSeek’s biggest problem: “too much, too long,” said Harley. On average, only Copilot wrote emails that were longer. On top of that, Gallo also called out DeepSeek’s “unnatural” use of too many multisyllabic words, such as “debilitating.” Deepseek is available at chat.deepseek.com. 1. Anthropic’s Claude Return to menu Score: 50 out of 100 Prompt 1: an apology letter Pamela Skillings: It communicates real human emotion and thoughtful consideration of the friend's feelings. Subject: A better conversation about sleep Hi [Friend's name], I've been thinking about our exchange about sleep deprivation, and I want to apologize. When I laughed and dismissed your experience with insomnia, that was insensitive of me. I didn't know about your health struggles with sleep, and even if I had, comparing our different experiences wasn't fair or kind. Being a parent has certainly changed my relationship with sleep, but that doesn't invalidate what you're going through with insomnia. Health problems that affect sleep can be truly debilitating, and I should have been more understanding. I value our friendship and miss our normal connection. I'd love to grab coffee sometime soon if you're open to it, or we can talk more about this if you'd prefer. [Your name] Erica Dhawan: Gets straight to the point with a strong, direct apology. Carmine Gallo: Who says this? People would say “being a parent is exhausting.” Erica Dhawan: Avoids justification and centers the friend’s feelings. Pamela Skillings: Overly formal language Ann Handley: YES. Nice job, friend. I think she'll forgive you with this one! Send Claude’s emails weren’t perfect — even it once fell into the “Hope this email finds you well” trap and other telltale phrases that Skillings said are “soooooo AI.” But on average, Claude’s emails felt more human than the others, and it landed about five points ahead of my human-written emails in the judge’s scores. Claude “uses precise, respectful language without being overly corporate or impersonal,” said Dhawan. “It was more structured, natural and emotionally attuned, making it feel more trustworthy than the others.” Gallo said Claude even showed a bit of “self-awareness” in the test email about layoffs: It gave details about the company’s severance offering and then added, “I recognize this package is modest.” What did Claude do better than a human? In business emails, Claude used research-backed arguments and seemed to anticipate objections that brought in context and ideas that I wouldn’t have thought of on my own. Claude was also able to crack a few jokes. In our test of a funny email to persuade a spouse to move to the North Pole, most of the AIs were just punny. But Claude went for some real chuckles. Near the beginning of its email, Claude wrote, “Before you start frantically googling ‘how to divorce someone who wants to live with polar bears,’ hear me out.” Said Skillings: “Okay, this is funny.” Claude is available at claude.ai. What did we learn? Return to menu Our five judges didn’t always agree on which emails were the best. But they homed in on a core issue you should be aware of while using AI: authenticity. Even if an AI was technically being “polite” in its writing, it could still come across as insincere to humans. Claude won out, on average, because it felt more natural. “The best AI isn’t just efficient — it builds connection by balancing warmth, clarity and emotional context,” said Dhawan. “This is the real challenge for AI-assisted communication going forward.”
Coincidently tonight my wife and I needed to write an email to a Realestate agency and we weren't quite sure how to write a good email. After reading the review above I sent "Claude.ai" a draft email. The result was very impressive I thought and I just polished it again to finish it off.