Best AI Email Assistant (2026): 10 Tools That Draft Your Replies, Compared

Short answer: to keep Gmail or Outlook and get replies drafted in your voice for the least money, start with Superhuman's Email Assistant at $12 a month on annual billing, or MailMaestro at $12 a seat. If you want the longest list of security paperwork plus a meeting notetaker, Fyxer is $37 a month on annual billing. Serif says it learns from every edit you make. Lindy goes past email and asks before it sends anything. For open source, or rules that can send replies on their own, use Inbox Zero. For a shared support@ inbox, Help Scout drafts from your help docs and past conversations. Updated November 9, 2026.

How we checked: prices, plan limits, supported mailboxes, send behavior, model names and security claims come from each vendor's own pricing, security, help or docs page, read November 9, 2026. Where a vendor's page does not state something, we say "Not stated". We did not test these assistants hands-on, so this guide compares published price, limits and features, not draft quality. Prices change often, so check the vendor before you pay.

Every tool here connects to your mailbox, reads incoming mail, sorts it, and writes a reply before you open the thread. Most put that reply in your normal Drafts folder, so you still press Send yourself. The real differences are in five places: price and how it is metered (seats or credits), whether it works with Outlook as well as Gmail, whether it can ever send without you, how it learns to sound like you, and what it says about security. The table below lines those up.

Fyxer works inside Gmail and Outlook. It labels incoming mail and writes replies in your tone, and its pricing page is clear that drafting starts on Pro: the Free plan has a daily briefing and 400 credits but no drafted replies and no inbox sorting. Pro is $37 a person a month on annual billing or $49 monthly, and Team is $64 or $99. Every sign-up starts with a 14-day Team trial. Paid plans include unlimited credits for the first 3 months as a launch offer, then 3,000 credits a month per member on Pro; sorting costs 0.2 credits an email.

Fyxer's security page says it "will never send an email on your behalf". Its data docs list SOC 2 Type II, ISO/IEC 27001, CASA Tier 2, UK and EU GDPR, and HIPAA on Enterprise. Not for: anyone who wants mail to go out without review, or anyone who does not want their email used to improve the vendor's own models without first changing a setting (see the privacy section below). It is also not the cheapest way to get drafts.

Superhuman now sells two things. The Email Assistant works inside your existing Gmail or Outlook: it labels mail as it arrives, drafts a reply for every message that needs one, archives low-priority mail and brings back threads that need a follow-up. It is $12 a month billed annually or $15 monthly, and it covers several Gmail and Outlook accounts. Superhuman says it learns how you write from the emails you have already sent and adapts to each recipient. Its FAQ says it does not send: "Nothing goes out without your approval."

The separate Superhuman Mail app is part of the Business plan on its plans page, at $33 a member a month on annual billing or $40 monthly. The Mail page says its AI can draft "and if you want" send emails for you. The Email Assistant page states SOC 2 Type 2 and GDPR. Not for: buyers who need to know which AI model reads their mail, since the pages we read do not name one, or anyone who wants it to send replies on its own.

Jace connects Gmail, Google Workspace, Outlook.com and Microsoft 365 accounts. It drafts replies for threads it labels Needs reply, saves them to your normal Drafts folder, and runs Flows such as creating a calendar event or using a connected tool. Its pricing page lists Plus at $25 a month or $20 on annual billing, with 10,000 credits and 2 inboxes, and Pro from $50 ($40 annual) with 20,000 credits and 8 inboxes. Larger Pro tiers go up to 2,400,000 credits. When credits run out, auto-drafts and chat pause until the next month, and unused credits do not roll over.

The 7-day trial asks for a card at checkout but charges $0 that day. Jace's homepage says Flows "create drafts for your review unless you change that", and that it follows "SOC 2 and CASA Tier 3 controls", which is worded more loosely than a stated certification. Not for: a busy shared inbox on a fixed budget, because auto-drafting on high volume uses credits fastest, or a security reviewer who needs a named audit report.

Lindy is a general AI assistant, and inbox work is one of its jobs. It links Gmail or Outlook, triages mail, pre-drafts replies in your voice, researches senders and schedules meetings. Its pricing page gives $50 of free credits for 7 days, then Team from $29.99 a month for 3,000 credits (higher tiers up to $149.99 for 20,000), with top-ups at $10 per 1,000. Drafting a reply counts as an everyday ask at 2 to 250 credits. You pick the model for each task from "most major models", but the page does not name the vendors.

The FAQ says anything with outside impact, such as sending an email, waits for your approval. Lindy's security page lists SOC 2 Type II, audited by Johanson Group, plus HIPAA, GDPR and PIPEDA; a signed BAA is on Enterprise. Not for: someone who only wants drafted replies. At $29.99 a month and up it costs about two and a half times Superhuman's Email Assistant on annual billing, and credit use varies by task.

Shortwave is a full email client, not a layer on top of Gmail. Its pricing page names its models: Claude Haiku 4.5, Claude Sonnet 4.6, and Claude Opus 4.6 on the top tier. Business is $30 a seat a month, Premier $45 and Max $120, each with a 14-day trial, and the billing docs say there is also a free plan. Paid plans learn how you write from the emails you send and offer one-click AI replies; for automatic drafting, Shortwave points to its sister product Tasklet.

Its security page says Shortwave passes a CASA Tier 2 audit every year, that its only sub-processors besides Google Cloud are OpenAI, Anthropic and Pinecone, and that "the vast majority" of its AI workloads run on open-source models on hardware it controls. For SOC 2 Type II, it asks organizations to contact its team. Not for: Outlook users. Shortwave's docs say Microsoft 365 and Exchange are not supported and it needs a Gmail or Google Workspace account.

Inbox Zero is an open-source assistant for Gmail and Outlook, under the AGPL-3.0 license on GitHub, and you can self-host it. The hosted pricing page lists Starter at $20 a user a month on annual billing ($25 monthly) with 2 email accounts, Plus at $28 ($35) and Professional at $40 ($50), each with a 7-day trial. The email app on its own is free.

Its docs say auto-drafts land in Drafts and are never sent automatically. Rules written in plain English can include "Send replies" or "Send email" actions, though, so it is the one personal assistant here that can answer on its own when you set it up to. It learns from your writing-style settings, your edits to its drafts, and a knowledge base you fill in. You can bring your own key for Anthropic, OpenAI, Azure OpenAI, Google, Groq, Cerebras, OpenRouter or Vercel AI Gateway; the default provider is not named. Not for: anyone who does not want to test rules before trusting them, or anyone who wants self-hosting without running servers and setting up their own Google or Microsoft OAuth app.

MailMaestro works as an Outlook add-in and a Gmail Chrome extension. Its pricing page lists a free plan with 3 AI requests a week, and Pro at $12 a seat a month billed annually ($144 a year), with unlimited auto labels, auto-drafts and auto follow-ups. It names its models as "ChatGPT, Claude, and more". The security page lists SOC 2 Type II, HIPAA with a BAA on request, Microsoft attestation, and CASA Tier 2.

Not for: Gmail users who want every Pro feature. MailMaestro's own FAQ says email reminders, Ask AI and attachment summaries are Outlook-only for now. Annual plans are not refundable after purchase.

Serif connects to Gmail or Outlook and pre-drafts replies you send or edit with one click. Its pricing page says it studies how you have written to different people, including tone, length, greetings and sign-offs, and "learns from every edit". Lite is $30 a month, Standard $50 with 5 times Lite's usage, Pro $200 with 20 times, and Team $50 a user, all billed monthly with a 7-day trial. Its security page lists SOC 2 Type 2, CASA Tier 2, HIPAA and GDPR, and says your emails are never stored on its servers.

Not for: buyers who need to know what they are paying for. Usage is described only as multiples of Lite, with no stated number of drafts, and the model provider is not named.

Gmelius is a shared-inbox and AI layer for Gmail. Its pricing page lists Meli, the AI assistant that drafts replies, sorts mail, schedules meetings and follows up, at $19 a user a month on annual billing or $21 monthly. Growth adds shared inboxes and automation rules at $25 ($33 monthly), and Pro is $40 ($50). Gmelius says Meli learns from the work that flows through your team's Gmail, Calendar and connected tools. It is SOC 2 Type II certified, per its security page.

Not for: Outlook. Gmelius counts a user as a Gmail or Google Workspace account. It also does not state which AI model it uses.

If your email is customer support, a personal assistant is the wrong shape. Help Scout is a shared inbox for teams. Its pricing page lists a Free plan (5 users, 1 inbox), Standard at $25 a user a month and Plus at $45, both on annual billing. AI Drafts, which "draft replies based on past conversations and help content", are unlimited on Plus and Pro. AI Answers, sold as the Envoy add-on, replies to customers in a chat widget from your knowledge base at $0.75 per resolution, with a monthly cap you set and a 3-month free trial.

Help Scout's AI transparency page says it uses OpenAI foundation models with light LoRA fine-tuning for tasks like tone, and its security page states SOC 2 Type 2 for security and availability, with HIPAA under a BAA. Not for: one person's inbox, or a team that wants to keep working inside Gmail.

Hiver is the other support-inbox option. Its pricing page lists Growth at $25 a user a month on annual billing or $35 monthly, with AI agents and an AI Copilot that drafts replies, a 2-seat minimum, and a version that runs inside Gmail. It lists SOC 2 Type II, ISO 27001 and HIPAA. It is a strong fit for a Gmail-based team, but Help Scout's free plan and clearly priced AI make it easier for a small team to start.

To draft replies, every one of these tools has to read your mail. Three questions are worth asking before you connect an account.

• Has it passed Google's security assessment? Google's security assessment page says apps that request restricted Gmail scopes "must undergo an annual security assessment" under the CASA framework. Fyxer, Shortwave, MailMaestro and Serif state CASA Tier 2. Jace says it follows CASA Tier 3 controls. Google's page now describes assurance levels (AL1 and AL2), so vendor "tier" wording may lag. CASA covers Google access only; it says nothing about Outlook.
• Will it train on my email? Lindy, Superhuman, Shortwave, MailMaestro and Serif all say your email is not used to train AI models (Superhuman and Shortwave say external or third-party models, Serif says general models). Fyxer is different: its data docs say it trains its own private models on customer content after replacing names and email addresses with codes, and you opt out under Dashboard, Settings, Account. On Enterprise, the opt-out is on by default.
• Which AI company sees the text? Most vendors do not say. Shortwave names Anthropic's Claude models and lists OpenAI and Anthropic as sub-processors. Help Scout names OpenAI. MailMaestro names ChatGPT and Claude. With Inbox Zero you can pick the provider and pay with your own key, or self-host so the mail never touches the vendor at all.

If your mail includes health data, Fyxer (Enterprise), Lindy (Enterprise), MailMaestro, Serif, Gmelius and Help Scout all mention HIPAA on their own pages; ask for the BAA before you connect the inbox.

• You want drafts and nothing else, as cheaply as possible: Superhuman Email Assistant at $12 a month annual, or MailMaestro at $12 a seat, especially on Outlook.
• Your security team will ask for documents: Fyxer lists SOC 2 Type II, ISO 27001 and CASA Tier 2; turn off model training if that matters to you.
• You want it to get better as you correct it: Serif learns from every edit; Inbox Zero shows its learned patterns so you can edit them.
• You are ready to switch email apps and use Gmail: Shortwave, which names its Claude models.
• Email is one of many chores: Lindy, with approvals before anything goes out.
• You want replies sent automatically, or to self-host: Inbox Zero.
• You answer customers from a shared address: Help Scout, or Hiver if your team lives in Gmail.

Whichever you pick, run the trial on your real inbox for a week and count how many drafts you send without editing. That number, not the feature list, tells you whether the subscription saves time. See also our Fyxer listing and Lindy listing.

What is the best AI email assistant in 2026?

It depends on your inbox. Superhuman's Email Assistant ($12 a month annual) and MailMaestro ($12 a seat annual) are the cheapest ways to get drafted replies inside Gmail or Outlook. Fyxer ($37 a month annual) lists the most security certifications. Serif learns from your edits, Shortwave is a Gmail client with named Claude models, and Inbox Zero is open source.

Which AI email assistant can send replies automatically?

Inbox Zero can, if you add a send action to one of its plain-English rules; its auto-drafts on their own are never sent. Lindy can send, but waits for your approval. Fyxer, Superhuman's Email Assistant and Serif say they only draft and you send. For customer support, Help Scout's AI Answers replies to customers in a chat widget at $0.75 per resolution.

Is there a free AI email assistant?

Inbox Zero is open source under AGPL-3.0 and free to self-host. MailMaestro has a free plan with 3 AI requests a week, and Shortwave has a free plan. Fyxer's free plan does not draft replies; drafting starts on Pro. Help Scout has a free plan for up to 5 users, but its AI Drafts start on Plus.

Which AI email assistants work with Outlook?

Fyxer, Superhuman's Email Assistant, Jace, Lindy, Inbox Zero, MailMaestro and Serif all support Outlook as well as Gmail. Shortwave and Gmelius are Gmail and Google Workspace only; Shortwave's docs say Microsoft 365 and Exchange are not supported.

What is CASA, and why do AI email assistants mention it?

CASA is the Cloud Application Security Assessment framework that Google uses for apps requesting restricted Gmail scopes, which must pass an assessment every year. Fyxer, Shortwave, MailMaestro and Serif state CASA Tier 2. It covers Google access only, not Outlook.

Do AI email assistants train on my emails?

Most say no: Lindy, Superhuman, Shortwave, MailMaestro and Serif state your email is not used to train AI models (some limit that to outside or general models). Fyxer trains its own private models on customer content after replacing names and addresses with codes, unless you opt out in settings; on Enterprise the opt-out is on by default.