Find the right AI writing assistant for personal replies, business messages, outreach, or campaigns. This ranked guide separates drafting tools from assistants that work inside your inbox.
Introduction
AI email writing tools can draft a message from a prompt, revise wording you have already written, or suggest a reply using the conversation in your inbox. The important distinction is access: a standalone drafting tool needs you to supply the relevant details, while an inbox-connected assistant may use the thread to shape its response.
This ranking focuses on how useful each tool is for writing actual emails, not just managing an inbox. It considers the quality of its drafting and revision features, where it fits into a workflow, compatibility with services such as Gmail or Outlook, and what access it needs to your messages. A tool that writes a polished first draft is not necessarily the right choice for someone who spends the day replying to long threads; an assistant that handles those threads may be unnecessary if you mainly write occasional outreach emails.
Key Findings
- ChatGPT is the strongest general-purpose choice for drafting varied emails and tailoring messages to different recipients.
- Google Gemini is the better fit for Gmail users who want writing help near the message they are answering.
- Microsoft Copilot is the clearest fit for Outlook users who need help replying within their existing workflow.
- Standalone writing tools require you to supply relevant email context and move the draft into your inbox.
- Review every suggested reply for incorrect commitments, omitted requests, and sensitive details that do not belong in the message.
The 10 Best AI Tools for Email Writing, Ranked
ChatGPT is the most flexible choice for drafting many kinds of email, but the best tool depends on where you write. Google Gemini and Microsoft Copilot rank higher for people who need help inside Gmail and Outlook. This ranking weighs writing range, access to email context, workflow fit, and the consequences of giving a tool message content.
1. ChatGPT
Best for: People who write varied emails and want close control over the message before it reaches their inbox.
ChatGPT works well as a drafting partner when the task changes from one message to the next. You can ask it to turn meeting notes into a follow-up, shorten a delicate response, propose several subject lines, or rewrite an announcement for different recipients. Its advantage is not a special email interface; it is the ability to work from detailed instructions. Give it the audience, purpose, facts that must remain intact, and an example of your preferred voice, and it can produce alternatives you can compare rather than a single suggested reply.
That flexibility makes ChatGPT the strongest general-purpose pick. For example, a manager can supply the decisions from a meeting and request one direct email to the team and a separate, more explanatory note to a client. A native inbox assistant may be quicker at replying to a thread, but ChatGPT is better suited to shaping two messages with different goals from the same source material.
The distinction is access. Using ChatGPT as a standalone writing tool does not, by itself, give it the Gmail or Outlook thread you are answering. You must supply the relevant context and move the draft back into the email composer. That extra step can be useful: it forces you to decide what information the model needs. It also makes ChatGPT less convenient for rapid, thread-by-thread replies. Don’t assume it knows an attachment’s contents, a prior agreement, or the recipient’s preferred tone unless you provide that information.
For Gmail and Outlook users, the dependable workflow is to draft or revise in ChatGPT, then paste the result into the appropriate composer and check it against the original thread. If you are handling confidential correspondence, avoid pasting entire conversations when a short, de-identified summary will do. ChatGPT is a good choice when writing quality and adaptability matter more than staying in the inbox; it is a weaker choice when the main job is responding to dozens of messages with their context already on screen.
2. Google Gemini
Best for: Gmail users who want to draft or revise without moving between an inbox and a separate writing window.
Gemini’s most important distinction is its Gmail workflow. Writing assistance in Gmail can help create a draft from an instruction, refine text in the composer, or suggest a response while you work on a message. That is more useful for an everyday reply than a standalone chatbot when the email itself supplies the context. You can start from “Thank them for the update, confirm Thursday, and ask for the revised agenda,” then inspect the proposed wording before sending.
Gemini is particularly sensible for someone whose day is already organized around Gmail. The drafting step sits near the message being answered, which reduces the chance of omitting a request buried in a thread. It can also help when you know what you mean but want a more concise or appropriately formal version. Its advantage over ChatGPT is proximity to the conversation, not necessarily a better grasp of your intent. A vague instruction can still produce a polished email that fails to answer the actual question.
Keep Gmail’s built-in assistance distinct from the standalone Gemini app. If you use the standalone app to write an email, the practical workflow again involves supplying context and moving text into Gmail. In Outlook, Gemini is not a native Outlook writing assistant; you would use it separately and transfer the draft. People who routinely work in both inboxes should not treat a good Gmail experience as evidence of an equivalent Outlook one.
Inbox context also deserves a privacy check. A draft informed by a thread can involve customer details, internal decisions, or personal information. Follow your organization’s rules for AI features in its email environment, and review the final message for details pulled from earlier correspondence that do not belong in the reply. Pick Gemini over a general chatbot if Gmail is where most of your email work happens. If Outlook is your primary inbox, Copilot is the more direct fit.
3. Microsoft Copilot
Best for: Outlook users who need help turning email threads and instructions into replies in their existing workflow.
Copilot’s place on this list rests on its Outlook integration. Writing within the email environment matters when a reply depends on the wording of an incoming request or the history of a conversation. Rather than moving that history into a separate chatbot, an Outlook user can work with drafting and rewriting assistance near the message they intend to send. Copilot can also help adjust a draft’s tone or length, which is often more valuable than generating an entire response from scratch.
Consider a project lead answering a long status email. The useful task is not “write a professional reply.” It is “acknowledge the delayed deliverable, confirm who owns the next step, and ask for a date without implying that the deadline has been approved.” Copilot is suited to that kind of work when the relevant Outlook context is available. The sender still needs to verify the commitments and dates: fluent wording is no safeguard against agreeing to something the team has not decided.
For Gmail, Copilot should not be treated as a native Gmail composer assistant. A Gmail user can use a separate Copilot writing interface and move the text into Gmail, but that is a different workflow from writing inside Outlook. The same distinction applies within Microsoft’s products: the Copilot experience you use outside Outlook is not a substitute for checking what information is available to the assistant in an Outlook message.
Copilot is the clearest AI email assistant for Outlook in this ranking, provided Outlook is already the center of your work. It is less compelling if you mainly need elaborate campaign copy or highly customized writing from a long creative brief; ChatGPT or a marketing-focused tool gives you a more deliberate drafting space. As with any assistant that can use workplace context, confirm your organization’s data-handling rules before using it on sensitive correspondence, and remove any unnecessary internal detail from the final reply.
4. Grammarly
Best for: Writers who usually know what to say but want help making an email clearer, shorter, or less abrupt.
Grammarly earns a high position because many email problems are revision problems. The facts are already in the draft, but the request is buried, the opening takes too long, or a sentence sounds sharper than intended. Grammarly’s writing suggestions and generative assistance are useful at that stage. It can flag mechanical errors, suggest clearer phrasing, and help rework tone without requiring you to abandon your original message.
That makes it distinct from an assistant whose main appeal is generating a reply from inbox context. If you write, “We still need the figures you promised last week,” Grammarly can help you phrase the reminder more constructively. It cannot decide whether “promised” accurately describes the agreement. The sender remains responsible for the substance, especially in a dispute or an escalation where a softer sentence might accidentally change the meaning.
Grammarly can be useful while composing in Gmail or Outlook through its supported writing surfaces, including browser-based workflows. The exact experience depends on where you compose: assistance in a web editor is not the same thing as native access to your entire mailbox, and support in a particular app should not be assumed from support in its browser version. If Grammarly is not available in your composer, you can revise text in a supported editor and move it back. In either case, it is best understood as a writing layer, not an inbox manager.
That boundary matters for privacy and accuracy. Text you ask Grammarly to analyze may contain names, account details, or other sensitive information; use it according to your organization’s policies. Choose Grammarly if you want to preserve your own reasoning and improve its expression. Choose Gemini, Copilot, or an inbox-focused assistant instead if your bigger problem is extracting the right points from long threads before you can write.
5. Shortwave
Best for: Gmail users willing to use a different email workspace to write and manage replies.
Shortwave is an email client built around a Gmail inbox, rather than a writing tool you paste into Gmail’s existing composer. Its AI writing function sits alongside the messages you are handling. That changes the job you can give the assistant: instead of describing an email from memory, you can work from the conversation in the client and draft a response in the same place.
This is a meaningful distinction for anyone who spends time reconstructing context. Suppose a thread contains several proposed meeting times and a final change of venue. An inbox-oriented tool can help form a reply while those messages are available in the workflow. You still need to check which proposal was final and whether the answer makes any unintended commitment. Context access reduces copying; it does not make a generated reply authoritative.
Shortwave is also a larger workflow decision than adding a browser writing aid. To get its central benefit, you use Shortwave as the place where you handle your Gmail mail. Someone satisfied with Gmail’s interface may prefer Gemini’s in-composer help rather than changing email clients. Shortwave is not the pick for an Outlook mailbox: its Gmail focus is a defining constraint, not a minor omission. An Outlook user looking for message-aware drafting should start with Copilot or an email workspace that supports Outlook.
Because Shortwave’s appeal is its ability to work with inbox material, consider which messages your organization permits an additional email client and its AI features to process. The appropriate comparison is not merely “Which tool writes a nicer sentence?” It is “Am I comfortable handling this mailbox in another workspace in exchange for a more connected drafting workflow?” Choose Shortwave when that exchange makes sense and Gmail is your primary inbox.
6. Superhuman
Best for: People who handle a high volume of individual email and want AI writing embedded in a dedicated email client.
Superhuman approaches email writing as one part of processing the inbox. Its AI assistance can help draft replies and reshape text within an email workspace designed for moving through conversations. That combination is different from opening ChatGPT whenever you need a paragraph: the writing aid is positioned where you read, decide, and respond.
Its strongest use case is the repeated small reply. Think of a person who needs to acknowledge introductions, answer scheduling questions, and follow up on decisions throughout the day. The benefit is not that every response should be generated. It is that a short instruction can get a workable draft into the reply flow, where the sender can correct the details and move on. For a sensitive negotiation or an unusual customer issue, that same speed can be a liability if it encourages a quick send without checking the conversation.
Unlike Shortwave’s Gmail-only focus, Superhuman is relevant to people working with Gmail or Outlook accounts. In either case, however, the writing experience takes place in Superhuman’s email workspace, not as a button inserted into the standard Gmail or Outlook interface. If your team must compose in its existing inbox for operational reasons, that distinction may decide the matter. It is also different from Grammarly, which is chiefly useful for improving text you have written rather than organizing the act of responding.
Connecting an inbox to another client has privacy and administrative implications. Check whether your organization permits that connection and how it expects staff to handle sensitive threads with AI assistance. Superhuman is a strong fit when you want both an email workspace and faster drafting. It is a poor fit if you only need occasional help phrasing a message and have no interest in changing how you read and send mail.
7. Jasper
Best for: Marketing teams producing email copy that must follow a defined brand voice across campaigns.
Jasper belongs in this ranking for a different kind of email work. A one-to-one reply is usually judged by whether it answers the recipient accurately. A marketing email may also need to match a brand’s vocabulary, campaign message, audience, and call to action. Jasper is oriented toward that content-production task: teams can use brand guidance and a creative brief to generate and revise copy intended for a consistent public voice.
For example, a team preparing a product announcement could ask for variants aimed at existing customers and new prospects, then compare how each version explains the same benefit. The useful output is a starting point for editorial review, not an automatically approved campaign. Someone must check claims against the actual product, confirm that the call to action matches the destination, and remove invented specificity. Brand consistency can make an email sound familiar; it does not establish that its factual statements are true.
Jasper is not primarily a native AI email assistant for Gmail or Outlook. If you use either inbox to send an individual message, you would generally draft in Jasper and transfer the text to the composer. That is a less direct workflow than Gemini or Copilot for answering a colleague. It makes more sense when a campaign brief and review process already sit outside the inbox. Nor should Jasper be confused with an email-sending platform simply because it writes campaign copy: producing text and preparing a campaign for delivery are separate jobs.
Teams should avoid feeding customer records or confidential correspondence into a brand-writing workflow merely to make copy feel personalized. Supply the audience characteristics and approved facts the writer needs instead. Choose Jasper when voice consistency across many marketing messages is the hard part. For a personal reply to this morning’s client email, an inbox assistant is a better match.
8. Copy.ai
Best for: Teams that need to produce and revise recurring outreach messages from a consistent set of inputs.
Copy.ai is useful when email writing is a repeatable process rather than a blank-page problem. A team might need an initial outreach message, a follow-up, and variations for distinct audiences, all based on the same approved description of its offering. Copy.ai’s workflow-oriented approach can help organize that generation process so writers are not rebuilding the same instructions for every draft.
The differentiator from ChatGPT is the emphasis on repeatability. In ChatGPT, an individual can write a detailed prompt and get an excellent draft. In a team workflow, the harder question is whether different people will supply the same required facts, apply the same constraints, and produce copy that a reviewer can assess consistently. A structured writing process helps with that, although the team still has to design the inputs and approve the results.
Copy.ai is not a substitute for knowing the recipient. An outreach sequence can sound specific while relying on assumptions that do not apply to a particular person or company. Before sending, check every claim about the recipient, remove unsupported familiarity, and make sure follow-ups reflect what has actually happened since the first message. The more messages a workflow produces, the more important that review becomes.
For Gmail and Outlook, treat Copy.ai as an external writing workflow unless you have separately established the connection your team intends to use. You can develop copy there and move approved text into either inbox; that does not give the tool native access to the thread being answered. Avoid supplying personal or confidential recipient information when a role, industry, or other broad description will serve the writing task. Choose Copy.ai when you need a repeatable process for outreach copy. Choose an inbox-based assistant when each email depends heavily on the live conversation in front of you.
9. MailerLite
Best for: Teams writing email newsletters and campaigns in the same environment where they prepare those sends.
MailerLite differs from most tools here because the email is a campaign asset, not a message to one person in an inbox. Its email creation workflow lets a team develop newsletter or campaign content in the setting where it will be assembled for subscribers. That proximity matters: a subject line, introduction, call to action, and layout have to work together. A strong paragraph generated elsewhere may need extensive changes once it is placed in the actual email.
Use MailerLite when the task is something like announcing an event to a subscriber list, not replying to an event attendee’s question. AI-assisted copy can help get past a first-draft bottleneck or suggest a different way to frame the message. It cannot verify event details, decide which claims the organization has approved, or judge whether a call to action is clear once the whole email is assembled. Review the completed campaign, not just the generated passage.
The Gmail and Outlook distinction is straightforward. MailerLite is not an AI email assistant inside either inbox. You might use Gmail or Outlook to discuss and approve campaign copy with colleagues, but the subscriber email is created in MailerLite. If the need is daily one-to-one correspondence, its campaign-focused environment adds the wrong kind of workflow. If the need is to create an email that combines copy with a subscriber-facing campaign, a standalone chatbot leaves more assembly to the team.
Subscriber information deserves particular care. A writing prompt usually needs the audience’s needs and the campaign’s approved facts, not identifiable subscriber records. Choose MailerLite when you want writing assistance close to campaign creation. Choose Jasper when the central challenge is producing on-brand copy for review across marketing activities, or an inbox assistant when you are answering individual messages.
10. Proton Scribe
Best for: Proton Mail users who want writing assistance without making a general-purpose chatbot their default place for sensitive email drafts.
Proton Scribe is a writing assistant for composing email in Proton Mail. Its position at the end of this ranking reflects a narrow fit, not an unimportant use case: it serves people who have already chosen Proton Mail and want drafting help within that environment. It can help turn an instruction into an email or improve wording while the user works on a message.
Its distinguishing consideration is how AI drafting fits into a privacy-conscious email workflow. That is not the same as a blanket promise that any text entered into any AI feature remains private under all circumstances. Processing choices and organizational requirements matter, and users should check the controls relevant to their setup before placing sensitive material in a prompt. Even when a drafting workflow is designed with privacy in mind, the final email still goes to its recipients; the tool cannot prevent a sender from including information that should not be shared.
Proton Scribe is not a writing layer for the standard Gmail or Outlook composer. If you use either service, you would need a separate drafting-and-transfer workflow rather than the Proton Mail experience that gives Scribe its purpose. For Gmail, Gemini is the more direct choice; for Outlook, Copilot is. Proton Scribe also is not intended to replace a marketing workflow that creates campaign assets or a general chatbot used for many kinds of writing.
Choose Proton Scribe if your email work takes place in Proton Mail and your decision centers on keeping drafting within that environment. Do not choose it solely because the word “privacy” appears in a feature description: establish what information your specific messages contain, how the drafting feature processes it, and whether the resulting email is appropriate to send. Its value lies in fitting a particular mail workflow, not in being the most adaptable writer on this list.
Quick Comparison
| Tool | Best use | Tool type | |||
|---|---|---|---|---|---|
| ChatGPT | Varied, highly directed drafts | Standalone writing assistant | |||
| Google Gemini | Everyday Gmail drafting | Gmail-integrated writing assistant | |||
| Microsoft Copilot | Replies in Outlook | Outlook-integrated writing assistant | |||
| Grammarly | Revising clarity and tone | Writing and revision layer | |||
| Shortwave | Gmail replies informed by inbox context | Gmail-focused email client | |||
| Superhuman | Fast individual replies | Email client with AI writing | |||
| Jasper | Brand-consistent marketing copy | Marketing writing platform | |||
| Copy.ai | Repeatable outreach copy | Workflow-oriented writing platform | |||
| MailerLite | Newsletter and campaign creation | Email campaign platform | |||
| Proton Scribe | Drafting in Proton Mail | Mail-integrated writing assistant |
How to Choose an Email Writing Tool for Your Workflow
Choose by the message you need to write and the information the tool needs to write it accurately. A general writing assistant suits varied emails; an inbox assistant is more useful when replies depend on an existing thread. For campaigns, look at marketing tools instead. If correspondence is sensitive, check what the tool can access and keep a review step before sending.
Match the tool to your email task
For occasional personal replies, ChatGPT can help turn a few points into a clear message. Grammarly is a better fit when you already have a draft and want to improve its wording. Neither should be treated as a substitute for checking names, dates, and commitments.
For business communication, consider where the draft starts. If you regularly respond to long threads in Gmail or Outlook, an assistant available in that workspace may be more useful than copying context into a separate app. If you write mostly new proposals or updates, drafting flexibility may matter more than inbox access.
Campaign emails and sales outreach are different jobs. MailerLite fits work centered on marketing emails, while Copy.ai or Jasper may suit teams developing message variants. When using AI for cold outreach emails, provide a real reason for contacting each recipient; polished wording cannot fix an irrelevant pitch.
Decide whether inbox integration matters
A writing assistant helps compose or revise text. AI email management tools may also help sort, search, or summarize inbox activity; Shortwave and Superhuman are worth considering if handling incoming mail is the bottleneck. An autonomous agent goes further by taking actions on a user’s behalf. Do not assume a drafting tool manages your inbox, or that an inbox assistant should send messages without your approval.
Before connecting sensitive correspondence, check which messages and contacts the tool can access. Then test one ordinary workflow: draft a reply, inspect what context it used, and confirm you can edit the result before it goes out.
Write Better Prompts and Review AI-Generated Emails
A useful email prompt specifies who will read the message, what you need them to do, and which facts must stay accurate. Treat the result as a draft, not a message ready to send: check its claims, attachments, tone, and handling of sensitive information before it reaches the recipient.
- Recipient context: Say who the recipient is, what they already know, and what relationship you have. “A client waiting for an update” gives the tool more to work with than “write a professional email.” Include only details you’re authorized to share.
- Objective: Name the action you want, such as confirming a meeting time or answering a question. If there’s a deadline, state it explicitly.
- Tone: Describe the relationship rather than relying on “friendly” or “formal.” To personalize AI-written emails, specify, for example, “warm and direct; acknowledge the delay without making excuses.”
- Length: Set a practical limit, such as “under 120 words,” and say if you want a subject line.
- Required facts: Supply verified dates, names, commitments, and next steps. Tell the tool not to invent missing details.
For example: “Draft a 100-word reply to a client who asked about the report. Apologize once for the delay, say I’ll send the revised report Thursday, and ask whether they need anything else. Keep it direct. Don’t invent a reason for the delay.”
Before entering a confidential thread or personal information, obtain any required consent and check the tool’s current data-handling documentation. Look at what inbox access it requests, who can access submitted content, retention rules, and whether content may be used for model training. If you cannot share the material, remove identifying details or draft without pasting the thread.
Finally, verify every name, date, claim, link, and promised attachment against your own records. Read the email aloud for phrasing that does not sound like you, then review the recipient field and full message yourself before sending.
Conclusion
The best AI email writing tool is the one that fits the message you need to send, the inbox you use, and the information you’re comfortable sharing—not simply the one that produces the smoothest first draft. Use the ranked entries to narrow your options, then apply the workflow criteria to decide whether you need flexible drafting, help with an existing thread, editing, or marketing email support. Before committing to a tool, try it on a representative message: a routine reply may reveal little, but a sensitive request or a thread with several constraints will show whether its suggestions are useful. Keep the final decision about what to say with the sender. Read every draft against the original conversation, correct unsupported details, and make sure the tone and requested action match your intent before sending.
Frequently Asked Questions
Which AI is best for writing emails?
ChatGPT is a strong all-purpose choice for drafting and personalizing different kinds of emails. If you mainly work in Gmail or Outlook, Google Gemini or Microsoft Copilot may fit more naturally into your workflow. Choose based on what you need most: flexible drafting, help within your inbox, careful revision, or marketing campaign copy.
Which AI email assistant works best with Outlook?
Microsoft Copilot is the most direct choice for writing assistance within Outlook. Other AI tools can help you draft or revise an Outlook email, but you may need to move text between applications. Before choosing, check which Copilot features and other integrations are available in the Outlook environment you use.
Which AI email assistant works best with Gmail?
Google Gemini is the most direct starting point for writing assistance within Gmail. Shortwave is an alternative if you want a different email workspace with inbox-focused assistance. ChatGPT can also draft messages you send through Gmail, but it needs you to provide any conversation context you want it to use.
Can ChatGPT write and personalize my emails?
Yes, ChatGPT can draft and personalize emails using the details you provide. Tell it who the recipient is, how you know them, what the message needs to accomplish, and what tone to use. Review the draft for accuracy before sending, and check the relevant data-handling settings before sharing sensitive correspondence.
Is another AI better than ChatGPT for email writing?
Yes, another tool may suit a specific email task better than ChatGPT. Gemini and Microsoft Copilot can be more convenient when you want help within Gmail or Outlook, respectively. Grammarly is useful when editing is the priority, while Jasper focuses on marketing copy. ChatGPT remains a flexible option for drafting many types of messages.
Do AI email writing tools use my messages to train their models?
Some may, but there is no single answer that applies to every AI email writing tool. How your messages are handled can depend on the product, your account settings, and whether you connect your inbox. Check the tool’s current documentation for model-training controls, retention, and access permissions before sharing sensitive correspondence.