Key Takeaways
- Lavender AI scores emails on a 1-100 scale based on analysis of nearly 2 billion sales emails, and emails scoring 95+ show 6% higher reply rates.
- Superhuman’s Business plan ($40/month) introduced Auto Drafts in October 2025, which writes follow-up emails automatically in your voice without prompting.
- Gmail Smart Compose is free for all Google Workspace and personal Gmail users, making it the lowest-barrier entry point for AI-assisted email writing.
- MailMaestro (formerly Flowrite) starts at $12/month and integrates directly into Outlook and Gmail without requiring you to switch email clients.
- SaneBox handles email prioritization rather than writing, but its filtering frees up time to focus on responses, with plans starting at $7/month.
- Copy.ai offers 30+ email-specific templates and is popular among marketers running outreach campaigns, with paid plans starting at $49/month.
- Shortwave launched Tasklet in October 2025, connecting email actions directly to Slack, Notion, Asana, and HubSpot.
- Grammarly Premium costs $12/month billed annually and catches tone mismatches in emails before you send them, a feature many overlook.
- Jasper AI’s Creator plan ($39/month billed annually) covers subject lines, body copy, and CTAs under one subscription alongside other content types.
- Missive starts at $14/seat/month and is the only tool on this list built specifically for team collaboration inside a shared inbox.
Writing a clear, professional email still takes more time than it should. You sit down to reply to a straightforward request and end up spending ten minutes tweaking the opening sentence. Multiply that across thirty or forty emails a day and the cost adds up fast. AI email writing tools attack this problem from several angles: some score your drafts and suggest improvements, some write entire emails from a short prompt, and some reshape your inbox so the right messages surface first.
The tools in this list were selected based on the quality of their AI output, the breadth of their email-specific features, pricing transparency, and real user feedback gathered from Reddit, Quora, and independent review sites. Whether you send cold outreach, manage a team inbox, or just want better grammar before hitting send, there is a tool here that fits your situation.
This guide covers 10 tools across different categories: dedicated sales email coaches, full-featured AI email clients, smart inbox managers, and general AI writing platforms that handle email as part of a broader content workflow. Pricing reflects information available as of mid-2025.
Lavender AI
Lavender is purpose-built for sales email. It sits inside your inbox as a browser extension (compatible with Gmail, Outlook, Salesloft, and Outreach) and scores every email you write on a scale of 1 to 100 in real time. The scoring engine draws on analysis of nearly 2 billion sales emails to identify patterns that predict reply rates. Emails that score 95 or above show a 6% higher reply rate, according to Lavender’s own research.
Beyond the score, Lavender flags specific problems: sentences that are too long, a subject line that reads as too salesy, or a body that buries the call to action. It also surfaces LinkedIn data on your prospect alongside the compose window so you can personalize without switching tabs. For cold outreach specifically, this combination of real-time coaching and prospect data is hard to beat.
Lavender is less useful if you send internal emails or general correspondence. Its coaching is calibrated for outreach scenarios, and the interface reflects that focus. But for sales reps, recruiters, and anyone whose income depends on reply rates, the feedback loop it creates is genuinely valuable.
Pros:
- Real-time email scoring based on nearly 2 billion sales emails
- Inline prospect data from LinkedIn reduces context switching
- Works directly inside Gmail, Outlook, and major sales platforms
- Specific, actionable feedback rather than generic suggestions
Cons:
- Focused on sales outreach, not useful for internal or casual email
- Free plan limits you to 5 emails per month
- Best features require a paid plan at $29/month or more
Pricing:
- Free: 5 emails per month, basic scoring
- Starter – $29/month: Email scoring, AI coaching, analytics
- Pro – $49/month: Deeper personalization, advanced insights
- Teams – $69/month: Team dashboards and collaboration features
Visit: Lavender AI
Superhuman
Superhuman is a full email client, not just a writing assistant. It replaces Gmail or Outlook as your primary inbox while adding a substantial AI layer on top. The keyboard-first interface is designed for speed: power users report processing their inbox significantly faster once they have the shortcuts memorized. But the AI features are what makes Superhuman stand out in 2025.
The October 2025 update introduced Auto Drafts, which automatically writes follow-up emails in your voice without requiring a manual prompt. It also added Auto Labels (automatic email categorization), Auto Archive (for marketing and cold emails), and Enhanced Voice and Tone that adapts writing style per recipient. The Business plan also includes Ask AI, which lets you query your entire email history conversationally. These are not incremental improvements but a significant step toward an email client that operates semi-autonomously.
The main friction point is price. At $30-40/month, Superhuman costs more than any other tool on this list, and some of its best AI features are locked to the Business tier. It currently supports Gmail and Outlook accounts only. For founders, executives, and sales professionals who process high volumes of email daily, the productivity gains can justify the cost. For lighter email users, it probably will not.
Pros:
- Auto Drafts writes follow-ups automatically in your voice
- Blazing fast keyboard-driven inbox with 100+ shortcuts
- Ask AI lets you query your email history conversationally
- HubSpot and Salesforce integration on Business plan
Cons:
- Starts at $30/month, making it one of the pricier options
- Best AI features (Auto Drafts, Ask AI) require the $40/month Business plan
- Supports Gmail and Outlook only
- Steep learning curve for keyboard shortcuts
Pricing:
- Starter – $30/month: Superhuman Mail, AI writing, shared conversations
- Business – $40/month: Auto Drafts, Ask AI, Custom Auto Labels, CRM integrations
- Enterprise: Custom pricing with SSO and dedicated support
Visit: Superhuman
Grammarly
Grammarly is the tool most people already have installed, often without realizing how useful it is for email specifically. Its browser extension and desktop app integrate with Gmail, Outlook, and most web-based email clients to provide live grammar, clarity, and tone suggestions as you type.
The tone detector is particularly useful for email. It reads your draft and shows you how your message is likely to come across, whether confident, apologetic, direct, or passive. For anyone who has accidentally sent an email that landed wrong, this feature alone is worth the price of admission. The Premium and Pro plans also include generative AI features with 2,000 monthly prompts, a brand voice setting, and the ability to write full email drafts from a short description.
Grammarly does not replace a dedicated email client or a sales coaching tool. It works best as a quality layer on top of whatever you already use. The free tier handles basic grammar and spelling, while Premium unlocks tone detection, clarity improvements, and full-draft generation. For teams, the Business plan adds style guides and consistency checks across the organization.
Pros:
- Tone detection prevents accidental miscommunication
- Integrates with Gmail, Outlook, and most web email clients
- Free plan covers basic grammar and spelling
- 2,000 monthly AI prompts on paid plans
Cons:
- Not a dedicated email tool, some email-specific features require Premium
- AI draft generation on free plan is very limited
- Business plan pricing can add up for larger teams
Pricing:
- Free: Basic grammar, spelling, and punctuation suggestions
- Premium – $12/month (billed annually): Tone detection, clarity, full AI generation
- Business – $15/member/month (billed annually): Team style guides, analytics
Visit: Grammarly
MailMaestro
MailMaestro began as Flowrite, one of the earlier dedicated AI email writing tools. After acquisition by Maestro Labs, it was rebuilt and relaunched with a broader feature set. The core idea remains the same: you give the tool a few bullet points or a short instruction and it writes a full, polished email. It works as a plugin inside Outlook and Gmail, so you do not need to switch email clients.
Where MailMaestro stands out is in style preservation. Users report that the generated emails retain personal quirks like their usual sign-off, punctuation habits, and preferred phrasing. The error rate in testing from reviewer sites sits around 2-3%, which is low but worth keeping in mind for anything that requires precision. The free plan allows 3 AI requests per week, which functions more as a trial than a practical daily driver. Paid plans start at $12/month and include unlimited composition, email summarization, and priority detection.
The TeamsMaestro plan ($17/month) adds meeting recording and transcription features for Zoom, Microsoft Teams, and Google Meet, which makes it an interesting option for anyone who writes a lot of meeting follow-up emails. The MaestroDuo package bundles both email and meeting tools at $25/month.
Pros:
- Preserves personal writing style in generated emails
- Works inside Outlook and Gmail as a plugin
- Meeting transcription on TeamsMaestro plan
- Unlimited composition on paid plans
Cons:
- Free plan limited to 3 requests per week
- 2-3% error rate requires proofreading before sending
- Less feature-rich than dedicated sales email tools like Lavender
Pricing:
- Free: 3 AI requests per week, basic features
- MailMaestro – $12/month: Unlimited composition, summarization, priority detection
- TeamsMaestro – $17/month: Email plus meeting recording and transcription
- MaestroDuo – $25/month: Both email and meeting tools bundled
Visit: MailMaestro
Shortwave
Shortwave is a Gmail-based email client with a strong AI layer that has been expanding its feature set rapidly through 2025. Its Ghostwriter feature learns your personal writing style and uses it to draft replies that match your voice. The AI assistant inside Shortwave supports multi-step reasoning: you can ask it to summarize a thread, find a specific email, or draft a response to a complex message, and it will break the task into sub-steps rather than giving a shallow answer.
In October 2025, Shortwave launched Tasklet, an AI automation platform that connects email actions to Slack, Notion, Asana, and HubSpot. This means you can set up automations like “when I receive an email from a client, create a task in Asana and post a summary to Slack” without leaving Shortwave. For teams that work across multiple productivity tools, this is a meaningful addition.
Shortwave works only with Gmail accounts, which limits its audience. The free plan restricts email history search to 90 days and adds a “Sent with Shortwave” signature. Personal and Pro plans remove these restrictions and add more connected accounts. For Gmail power users who want an AI-native client without paying Superhuman prices, Shortwave is the closest alternative. You can learn more about AI email clients on AI email tools guide.
Pros:
- Ghostwriter learns and matches your personal writing style
- Tasklet connects email to Slack, Notion, Asana, HubSpot
- Multi-step AI reasoning for complex email queries
- More affordable than Superhuman at comparable tiers
Cons:
- Gmail only, no Outlook support
- Free plan adds a mandatory signature to outgoing emails
- Free plan limits email history search to 90 days
Pricing:
- Free: 1 account, 90-day search history, Shortwave signature on emails
- Personal – ~$8/month: Signature removed, unlimited search history
- Pro – ~$15/month: Up to 3 accounts, advanced AI features
- Business – ~$25/month: Up to 10 accounts, team collaboration
Visit: Shortwave
Copy.ai
Copy.ai is primarily known as a general-purpose AI writing platform, but it has built a substantial set of email-specific features that make it useful for marketers and content teams. It offers more than 30 email templates covering subject lines, body copy, onboarding sequences, promotional campaigns, newsletters, and re-engagement emails. The brand voice feature lets you train the tool on your existing content so generated emails match your company’s tone.
The platform’s Workflows feature (available on paid plans) allows you to build multi-step automations: for example, pulling a prospect’s LinkedIn profile data, feeding it into an email template, and outputting a personalized draft at scale. This makes Copy.ai one of the stronger options for teams running email outreach campaigns at volume. The tool also supports more than 25 languages, which matters if your audience spans multiple regions.
The main limitation is that Copy.ai is not an email client. It generates content you then paste into Gmail, Outlook, or your sales platform. There is no inbox management, no tone scoring, and no CRM integration built in. For raw content generation across email and other channels, it is efficient and well-priced relative to its output quality.
Pros:
- 30+ dedicated email templates for multiple use cases
- Brand voice training ensures consistent messaging
- Workflow automation for personalized outreach at scale
- Supports 25+ languages for international campaigns
Cons:
- Not an email client, content must be pasted manually
- No inbox management or real-time coaching features
- Paid plans start at $49/month
Pricing:
- Free: Limited access to templates and AI generation
- Starter – $49/month: Unlimited AI generation, all templates, brand voice
- Advanced – $249/month: Workflows, API access, priority support
- Enterprise: Custom pricing for large teams
Visit: Copy.ai
Jasper AI
Jasper AI is one of the most established AI writing platforms and has built up a library of more than 100 purpose-built templates covering marketing copy across multiple formats. For email specifically, it handles subject lines, body copy, calls to action, and full campaign sequences. The Jasper Canvas (its long-form editor) works well for writing multi-part email sequences where consistency across messages matters.
The brand voice feature is Jasper’s strongest differentiator. You can upload examples of your existing content and Jasper will calibrate its output to match your style. This is valuable for marketing teams that need AI-generated email copy to sound indistinguishable from content written by their own team. Jasper also integrates with Grammarly, which adds an automatic quality check on top of the generated drafts.
Jasper is less suited to individuals who only need help with occasional emails. Its pricing starts at $39/month billed annually, and it makes most sense for marketing teams or agencies producing large volumes of content across email and other channels. The 7-day money-back guarantee on Creator and Pro plans lets you test it without long-term commitment. For more AI writing options, see our best AI writing tools roundup.
Pros:
- 100+ templates including email-specific formats
- Brand voice training for consistent messaging at scale
- Integrates with Grammarly for automated quality checks
- 7-day money-back guarantee on Creator and Pro plans
Cons:
- Priced for teams and agencies, not casual individual users
- Not an email client, requires pasting output into your email tool
- Enterprise plan pricing requires a sales conversation
Pricing:
- Creator – $39/month (billed annually): One user, all templates, brand voice
- Pro – $59/month (billed annually): Multiple brands, team collaboration
- Business: Custom pricing for larger teams with security and SSO
Visit: Jasper AI
Gmail Smart Compose and Help Me Write
Gmail’s built-in AI features are the most accessible on this list because they require no additional subscription for personal Gmail users or Google Workspace subscribers. Smart Compose offers real-time phrase completions as you type, trained on a neural language model and personalized to your writing patterns over time. You accept suggestions by pressing Tab, which speeds up routine email writing without disrupting your flow.
Help Me Write is the more powerful of the two features. It takes a short prompt and generates a full email draft directly inside the Gmail compose window. As of 2025, it is powered by Gemini and handles context from the email thread you are replying to. You can also use it to refine an existing draft: shorten it, formalize the tone, or elaborate on a specific point. The Suggested Replies feature (an update to the older Smart Reply) generates context-aware one-click response options for quick replies.
The tradeoff is depth. Google’s tools are broad rather than specialized. They will not coach you on reply rates or learn your prospect’s LinkedIn profile. But for anyone who writes emails inside Gmail and does not want to pay for a separate tool, Smart Compose and Help Me Write are genuinely useful starting points. They require no setup and no extra cost if you already use Gmail or Google Workspace.
Pros:
- Free for all Gmail and Google Workspace users
- No setup required, works inside the standard Gmail interface
- Help Me Write generates full drafts from short prompts
- Powered by Gemini with thread-context awareness
Cons:
- No specialized sales coaching or reply-rate optimization
- Limited customization compared to dedicated email AI tools
- Only available inside Gmail, not other email clients
Pricing:
- Free (personal Gmail): Smart Compose, Help Me Write, Suggested Replies
- Google Workspace plans – from $6/user/month: Same features plus enterprise controls
Visit: Gmail
SaneBox
SaneBox takes a different approach from every other tool on this list. It does not write emails for you. Instead, it uses AI to sort your incoming mail so that important messages surface at the top and everything else waits in filtered folders (SaneLater, SaneNews, SaneBlackHole). The premise is that better email management frees up the mental bandwidth to write better replies.
It works across any email client and any email provider, including Gmail, Outlook, Apple Mail, and Yahoo. Setup takes a few minutes and involves no app installation: SaneBox connects to your account via IMAP and begins sorting based on your behavior patterns. If it misfiles something, you move it back to the inbox and it learns from the correction. Features like SaneNoReplies (tracking emails you sent but never got a response to) and Reminders (snoozing emails for follow-up) make it more than a basic filter.
The Snack plan at $7/month gives you one account and two features. The Dinner plan at $36/month supports four accounts and all features, which suits professionals managing multiple inboxes. The 14-day free trial requires no credit card.
Pros:
- Works with any email client and any provider
- SaneNoReplies tracks unanswered outgoing emails
- Learns from corrections quickly
- 14-day free trial, no credit card required
Cons:
- Does not write or improve emails, only sorts them
- Requires trusting a third-party service with inbox access
- Free trial ends after 14 days, no permanent free plan
Pricing:
- Snack – $7/month: 1 account, 2 features
- Lunch – $12/month: 2 accounts, 6 features
- Dinner – $36/month: 4 accounts, all features
Visit: SaneBox
Missive
Missive is built for teams that manage shared inboxes. It combines a collaborative email client with an AI writing assistant, internal chat, and task management. Multiple team members can work on the same email thread simultaneously, leave internal notes, assign conversations to specific colleagues, and co-author drafts before anything goes out to the recipient.
The AI assistant sits in a sidebar next to each conversation. You can highlight a message and ask it to summarize, translate, rewrite in a different tone, or suggest a reply based on the thread context. Automations can trigger based on email content: an email from a client containing the word “refund” can automatically create a task and notify the support team. Reddit users cite Missive specifically for customer support workflows, with one user noting that the ability to “assign tasks and chat within the email thread” transformed their team’s inbox management.
Missive is not designed for individual users. The per-seat pricing and shared inbox model make sense for support teams, agencies, and small businesses. The Starter plan at $14/seat/month covers one shared inbox. The Productive plan at $18/seat/month unlocks unlimited shared inboxes, advanced automation, and AI-assisted drafting. Check out our guide to the top AI tools for related recommendations.
Pros:
- Real-time collaboration on email drafts across team members
- AI summarization and reply suggestions in a sidebar
- Automation rules triggered by email content
- Internal chat and task assignment within threads
Cons:
- Per-seat pricing, not cost-effective for solo users
- Steeper setup compared to simpler writing tools
- AI features require the Productive plan at $18/seat/month
Pricing:
- Free: 1 user, basic features, limited message history
- Starter – $14/seat/month: 1 shared inbox, internal chat, basic rules
- Productive – $18/seat/month: Unlimited shared inboxes, AI drafting, advanced automation
- Business – $26/seat/month: Priority support, audit logs, custom integrations
Visit: Missive
How We Evaluated These Tools
Each tool on this list was assessed against four criteria. First, AI output quality: does the generated email actually read as natural and useful, or does it sound robotic and generic? Second, email-specific features: does the tool offer functionality designed for email (tone detection, scoring, threading awareness) rather than just general text generation dropped into an email context? Third, pricing and value: is the cost proportionate to what you get, and is there a free plan or trial that lets you test before committing? Fourth, integration: does the tool work inside your existing email client, or does it require a workflow change?
No tool on this list was included based on marketing claims alone. Pricing was cross-referenced against official pricing pages and third-party review sites. Where possible, real user feedback from Reddit, Quora, and review platforms was used to validate or qualify vendor claims.
Which Tool Should You Choose?
| If you are… | Best option |
|---|---|
| A sales rep who lives in cold email | Lavender AI |
| An executive or founder processing high email volume | Superhuman (Business plan) |
| A Gmail user who wants no extra cost | Gmail Smart Compose + Help Me Write |
| A marketer writing campaigns at scale | Copy.ai or Jasper AI |
| A team managing a shared customer support inbox | Missive |
| Someone who wants better emails inside Outlook | MailMaestro |
| A Gmail power user wanting an AI-native client | Shortwave |
| Anyone drowning in unimportant incoming mail | SaneBox |
| A writer who wants grammar and tone help | Grammarly Premium |
Frequently Asked Questions
What is the best free AI email writing tool?
Gmail’s Smart Compose and Help Me Write features are the strongest free options because they require no extra signup or cost if you already use Gmail. Grammarly’s free plan covers grammar and basic clarity. Lavender AI’s free plan is limited to 5 emails per month, which is enough to trial the tool but not for daily use. MailMaestro’s free plan allows 3 AI requests per week.
Can AI write cold emails that actually get replies?
AI tools can improve cold email reply rates when used correctly, but generic AI output often performs poorly. Lavender AI’s coaching is built on data from nearly 2 billion sales emails and its research shows that emails scoring 95+ on its system achieve 6% higher reply rates. The key is using AI to personalize and improve a draft, not to generate a template sent unchanged to hundreds of people. Buyers in 2025 have developed pattern recognition for formulaic AI emails.
Do AI email tools work with Outlook?
Several tools on this list work with Outlook. MailMaestro integrates directly with Outlook as a plugin. Grammarly has an Outlook add-in available on all paid plans. Lavender AI supports Outlook alongside Gmail and major sales platforms. SaneBox works with any email provider via IMAP, including Outlook. Superhuman supports Outlook accounts in addition to Gmail.
Is it safe to give an AI tool access to my inbox?
Most AI email tools connect to your inbox via official OAuth or IMAP standards, which means they do not store your password. However, you are granting read access to email content, which means you should review each tool’s privacy policy before connecting. Tools like SaneBox are explicit about their data handling. For enterprise users, check whether the vendor is SOC 2 certified and whether they use your data to train their models.
How much time can AI email tools save per week?
A Gallup Q3 2025 report found that 45% of U.S. employees now use AI at work. Independent estimates from tool vendors and productivity researchers suggest that AI email assistants save users between 2 and 4 hours per week on routine email tasks, though this varies significantly by role and email volume. Users who process dozens of emails daily tend to see larger gains than occasional email senders.
What is the difference between an AI email writer and an AI email client?
An AI email writer (like Copy.ai, Jasper, or Lavender) generates or improves email content but does not manage your inbox. You write or receive emails in your usual client and use the AI tool as a layer on top. An AI email client (like Superhuman or Shortwave) replaces your existing email app entirely and combines inbox management with AI writing features in one interface. The right choice depends on whether you want to augment your current workflow or replace it.
Which AI email tool is best for small business owners?
Small business owners typically benefit most from tools that cover multiple use cases without requiring a large team setup. MailMaestro ($12/month) works inside both Gmail and Outlook and handles composition, reply generation, and summarization. Grammarly Premium ($12/month billed annually) is a safe choice if the main need is tone and clarity. For small businesses that run customer-facing email through a shared inbox, Missive’s Starter plan at $14/seat/month offers collaboration features that solo tools cannot match.
Can I use AI to write email subject lines?
Yes. Several tools on this list specialize in subject line generation. Copy.ai has a dedicated subject line template. Jasper AI includes subject line apps among its 100+ templates. Lavender AI evaluates your subject line as part of its overall email score and flags patterns that correlate with lower open rates. For Gmail users, Help Me Write can generate subject lines as part of a full draft.
What AI tools help with email tone?
Grammarly Premium is the most focused option for tone detection. It reads your draft and shows how it is likely to be perceived before you send it. Superhuman’s Enhanced Voice and Tone feature (on the Business plan) adapts writing style per recipient. Lavender AI’s scoring also includes tone as a factor, particularly for sales email. Shortwave’s Ghostwriter learns your personal tone over time and maintains it in generated drafts.
AI email writing tools have moved well past basic autocomplete. The best ones today act as real-time coaches, full inbox managers, or high-volume content engines depending on what you need. If you send cold outreach and reply rates matter, Lavender is worth the cost. If you live in Gmail and want zero extra spending, start with Help Me Write. Teams managing shared inboxes should take a close look at Missive, while high-volume email executives will likely justify Superhuman’s price through recovered hours.
The clearest mistake to avoid is choosing a tool based on its feature list rather than your actual email workflow. Start with the free plan or trial of whichever tool fits your situation most closely, measure whether it actually saves time or improves outcomes, and then decide whether to invest in a paid tier.
