AI Email Writing Showdown: Which Assistant Writes Best?

To objectively evaluate the email-writing prowess of AI tools, a structured "bake-off" was conducted. Five AI assistants – ChatGPT, Claude, Copilot, DeepSeek, and Gemini – were tasked with drafting five specific types of difficult emails, encompassing both professional and personal scenarios. These prompts included: an apology letter for an insensitive remark, a CEO's layoff announcement, a humorous request to a spouse, a peculiar work proposal, and a breakup message. To provide a benchmark for human-like quality, the author also drafted their own versions of these emails. A panel of esteemed communications experts, including Erica Dhawan, Carmine Gallo, Ann Handley, Shari Harley, and Pamela Skillings, then reviewed all generated emails in a blind tasting. They scored each email based on its clarity, tone, authenticity, and overall effectiveness, leading to a comprehensive ranking of the AI contenders.

Microsoft Copilot, integrated into various Microsoft products, landed at the bottom of the rankings with a score of 23 out of 100. Judges consistently found Copilot's emails to sound "robotic" and "impersonal," often beginning with generic phrases like "hope you're well." Its "tone-deaf" responses were a recurring issue, particularly in sensitive situations like layoff announcements, where it employed "stilted, robotic language." Copilot also proved to be the wordiest AI, often using twice as many words as other bots to convey the same message. For instance, its breakup message ended with the awkward phrase, "I hope we can keep things amicable," which judges questioned for its lack of natural phrasing. Copilot is accessible via copilot.microsoft.com and is included in Microsoft 365 subscriptions.

Google's Gemini, built into Gmail, received a score of 44 out of 100. A significant portion of the judges found its output easily identifiable as AI-generated, with comments like, "I don’t feel like it came from a real person." While Gemini's breakup message was praised for its simplicity and ability to "cause the least damage," and its argumentative emails were noted as "comprehensive and well-organized" with good acknowledgment of objections, it generally lacked the emotional resonance that makes an email feel personal. The judges felt that a friend would likely write a more heartfelt message. Gemini is available at gemini.google.com and within Gmail with a Google One subscription.

Anthropic's Claude emerged as the top performer, scoring 50 out of 100 and even surpassing the author's human-written emails in judges' scores. Claude's emails were consistently described as more "natural," "structured," and "emotionally attuned," fostering a sense of trustworthiness. Dhawan noted its use of "precise, respectful language without being overly corporate or impersonal." In the layoff announcement, Claude demonstrated "self-awareness" by acknowledging the modesty of the severance package. Claude also excelled in creative and humorous contexts, such as the North Pole move proposal, where its witty opening line, "Before you start frantically googling ‘how to divorce someone who wants to live with polar bears,’ hear me out," was particularly praised for its humor and effectiveness. Claude is available at claude.ai.

The communications experts provided valuable insights into the role of AI in writing. While acknowledging AI's utility for generating outlines, improving clarity, and offering ideas, they cautioned against relying on it entirely. Judges noted that AI-generated content can often be "stilted, formal, robotic and lack personalization, emotion and empathy." They stressed the importance of always editing AI drafts to ensure authenticity and prevent recipients from doubting the source, especially when delivering difficult messages. As Harley advised, "A hard message will become even harder if the recipient doubts the authenticity of the source." Ultimately, AI tools are best used as starting points, with human oversight and editing being essential for truly effective and empathetic communication.