We Tested 10 AI Email Writing Assistants — Here's What's Actually Worth It

An AI email writing assistant is software that uses artificial intelligence to help you compose, edit, and optimize emails more effectively and efficiently. These tools span a wide range of capabilities: grammar and style checkers like Grammarly catch errors, improve clarity, and suggest tone adjustments in real-time as you type. Full email generators like Jasper and Copy.ai can produce complete email drafts from brief prompts or bullet points, handling everything from marketing newsletters to sales outreach. Sales-specific tools like Lavender go further by scoring your emails on effectiveness metrics and providing real-time coaching to improve reply rates. Some tools operate as browser extensions that work within Gmail or Outlook, while others are standalone platforms. The common thread is using AI to reduce the time and effort required to write professional, engaging emails.

Yes, advanced AI writing assistants can learn and replicate your unique writing style with impressive accuracy. Jasper offers a brand voice training feature where you can upload examples of your writing, and the AI will match your tone, vocabulary, and sentence structure in generated content. MailMaestro analyzes your past email history to learn how you communicate and generates drafts that mirror your personal style. Grammarly adapts its tone suggestions based on your preferences, learning over time whether you tend toward formal or casual communication. The key to getting natural-sounding output is providing the AI with sufficient examples of your writing and refining the results during the first few weeks of use. Most users find that after an initial adjustment period, AI-generated drafts require only minor tweaks to feel authentically theirs — saving significant time while maintaining their personal voice.

Yes, AI-written emails can be highly effective for sales when used as a starting point and enhanced with personal touches. Studies and user reports indicate that AI-generated sales emails can achieve comparable or even better engagement metrics than fully manual emails, particularly when volume is a factor. Tools like Lavender are specifically designed for sales email optimization — they score your email on factors like readability, length, personalization, and subject line effectiveness, then provide real-time coaching to improve each message before you send it. The most successful approach is to use AI to generate an initial draft that handles structure, value proposition framing, and call-to-action placement, then add prospect-specific details and personal observations that demonstrate genuine research. This hybrid approach combines the consistency and speed of AI with the authenticity that drives meaningful sales conversations.

Language coverage varies significantly across AI email writing assistants. Grammarly supports grammar and style checking in over 20 languages, with the most comprehensive features available for English. Jasper and Copy.ai support content generation in 30 or more languages, leveraging large language models that have been trained on multilingual datasets. Writesonic and Rytr also offer broad multilingual support for email content creation. Accuracy and natural-sounding output are strongest for English, with steadily improving quality for major European languages like German, French, Spanish, and Portuguese, as well as widely spoken Asian languages like Japanese and Chinese. For business-critical communications in non-English languages, it is advisable to have a native speaker review AI-generated content, as nuances in tone, formality levels, and cultural context can sometimes be missed. Most tools are continuously improving their multilingual capabilities with each model update.

Most AI email writing assistants integrate seamlessly with popular email clients through browser extensions or native plugins. Grammarly offers the broadest compatibility, working across over 500,000 apps and websites including Gmail, Outlook, LinkedIn, and virtually any text field in your browser via its Chrome, Firefox, Safari, and Edge extensions. MailMaestro provides a direct integration with Microsoft Outlook as a native add-in, bringing AI drafting and summarization directly into your inbox workflow. Lavender operates as a Chrome extension for Gmail and also integrates with sales engagement platforms like Outreach and Salesloft. Jasper and Copy.ai work primarily through their own web interfaces but offer browser extensions for quick access. Flowrite integrates with Gmail and LinkedIn via a Chrome extension. When choosing a tool, check whether it supports your specific email client and whether the integration is a lightweight overlay or a deep native connection, as this affects the smoothness of the writing experience.