Inbox Zero
Inbox Zero Inc. · Inbox Zero: AI Email Assistant That Runs Plain-English Rules on Gmail and Outlook, Plus a Free Email Client
Inbox Zero is an AI email assistant for Gmail and Outlook that runs rules you write in plain English to label, archive, forward and pre-draft replies in your voice as mail arrives, with reply tracking, bulk unsubscribe and a cold email blocker. It suits people and small teams who want triage running in the background of their existing inbox, and its code is public on GitHub and self-hostable under AGPL-3.0 with added commercial terms. A separate keyboard-first email client is free on web, Mac, Windows and iPhone.
Best for
Founders, executives, salespeople, consultants and small teams on Gmail or Outlook who get a lot of email and want rules they can read and edit to sort it, draft replies and track follow-ups in the background, plus technical users who want to bring their own model key, script the assistant through an API or MCP, or self-host it for personal use
Not ideal for
People on email providers other than Gmail or Outlook, companies with five or more users that want to self-host without buying an enterprise license, anyone who wants AI triage at no cost on the hosted service, and teams looking for a general assistant that acts across many business apps rather than one focused on email and calendar
Who it's for
Busy professionals, founders, executives and small teams on Gmail, Google Workspace, Outlook or Microsoft 365, plus developers who want a self-hostable, scriptable email assistant
Capabilities
- Plain-English rules: describe how mail should be handled and Inbox Zero generates rules with AI or static (From, To, Subject) conditions and one or more actions, including label, move to folder, archive, forward, draft reply, send reply, mark as read, star, mark as spam, add to digest, call webhook and add a Todoist task
- Pre-drafts replies in your tone and style for emails that need an answer, using your past emails and calendar, and leaves them in the drafts folder for you to edit and send
- AI placeholders in rule templates: text inside {{double braces}} is written from the email's context while the rest of the template stays as you wrote it
- Rule testing against real or pasted emails without applying actions, a History log of what each rule did, a Fix workflow to correct wrong matches, and learned sender and domain patterns
- Delayed actions that run from 1 minute to 90 days after a match, and scheduled email digests that bundle mail from selected rules into one summary
- Reply Zero labels conversations To Reply or Awaiting Reply and adds Follow-up reminders after a configurable number of days, with optional auto-drafted nudges
- Bulk Unsubscribe and Bulk Archive for clearing newsletters and years of old mail, plus an AI cold email blocker and email analytics on volume, response time and assistant activity
- Calendar integration for drafting scheduling replies from real availability, booking links, and AI meeting briefs before calls with external guests
- Chat with the assistant to search, summarize and clean up the inbox from the web app, Slack, Microsoft Teams or Telegram, with confirmation before high-impact actions such as sending
- Plus plan and above: an AI meeting notetaker for Google Meet, Zoom and Teams calls, auto-filing of attachments to Google Drive or OneDrive, and context integrations (early access) that let drafts and briefs look up Notion, Stripe, Linear, Attio, HubSpot, Salesforce and other tools
- Free email client for Gmail and Outlook on web, Mac, Windows and iPhone with keyboard shortcuts, a command palette, a split inbox, all accounts in one view and private team comments on threads
- Bring your own model key on the hosted service (Anthropic, OpenAI, Azure OpenAI, Google, Groq, Cerebras, OpenRouter or Vercel AI Gateway), and a sensitive-data policy that can redact or block detected credentials and card numbers before content reaches the model
- REST API with scoped, per-inbox keys for stats, rules and unsubscribing, an API CLI, and an OAuth MCP server that lets ChatGPT, Claude or Cursor search mail, read threads, create drafts and manage rules, with sending behind a separate permission
- Organizations with Owner, Admin and Member roles and admin-managed rules copied to every member's inbox; member analytics are shared with admins only by consent
- Self-hosting with a setup CLI and Docker Compose, plus guides for Vercel, Kubernetes (Helm), AWS and Google Cloud
Limitations
- The AI assistant has no free plan: Starter, Plus and Professional each start with a 7-day trial that requires a credit card, and only the email client is free
- Only Gmail and Google Workspace, and Outlook and Microsoft 365 mailboxes are supported; other IMAP providers are not documented
- Outlook shared mailboxes accessed through your own account are not supported, and managed Microsoft 365 tenants may need an administrator to approve the app
- The license is AGPL-3.0 with added terms: you may not sell or monetize the software without written permission, and organizations with five or more business users need an enterprise license before running the code themselves, for example by self-hosting it
- Self-hosting means running Postgres and Redis, registering your own Google OAuth app (with Google Pub/Sub for Gmail push notifications) or Microsoft app, and paying for your own model provider
- Slack, app integrations, email digests, auto-filing, the meeting notetaker and an unlimited knowledge base require Plus ($28 per user per month billed annually) or higher; Starter has a limited knowledge base, and two email accounts per user are listed only from Plus up
- Rules run automatically once enabled, and the docs warn that a rule can match an unexpected message and a draft can omit context or make unsupported assumptions
- Reply Zero, Deep Clean, the meeting recorder and context integrations are listed as early access, and Deep Clean works with Gmail accounts only
- The iPhone app is not open source, and the Android app is an older app that Inbox Zero says is due for an update
Use cases
- Writing a rule such as 'if someone asks to set up a call, draft a reply offering times from my calendar' and having the draft waiting before you open the email
- Unsubscribing from dozens of newsletters and bulk archiving years of old promotional mail during a first cleanup
- Tracking which threads still need your reply and which are waiting on someone else, with a Follow-up label when a contact has not replied after three days (the default, weekends excluded)
- Routing invoices to a Finance label and auto-saving their PDF attachments to a Google Drive or OneDrive folder
- Asking the assistant from Slack or Telegram to summarize what came in overnight and approve a drafted reply from your phone
- Letting Claude or Cursor search your inbox and create draft replies through the MCP server while sending stays with you
Our take
Inbox Zero's strength is how inspectable it is: every behavior is a rule you can read, test against real mail, see in a history log and correct, which matters when software is archiving and drafting on your behalf. The bring-your-own-key option, scoped API, MCP server and self-hosting make it unusually open for a hosted product. Two things limit it. The AI is paid from the first plan, with Slack and integrations held for Plus. And the public code is not a free pass for companies: the added license terms require an enterprise license for any organization with five or more business users that runs the code itself. Individuals and small teams on Gmail or Outlook get the most from it, especially if they want control over the model and the rules.
Who should use it
Individuals and small teams on Gmail, Google Workspace, Outlook or Microsoft 365 who handle a steady stream of email and want it sorted, drafted and followed up on with rules they control, developers who want to automate their inbox through an API or MCP, and privacy-minded users who want to self-host for personal use or bring their own model key.
Who should skip it
Anyone on an email provider other than Gmail or Outlook, organizations of five or more users that plan to self-host without an enterprise license, people who want AI triage without paying after the trial, and teams that want one assistant acting across CRMs, project tools and documents rather than an email-focused one.
Strengths
- Rules are written in plain English but stay inspectable, testable and fixable, so you can see why an email was handled the way it was
- Works in the background of your existing Gmail or Outlook, so nothing needs to be migrated and the separate email client is optional
- Bring-your-own model key on the hosted service and a long list of providers, including local models, when self-hosted
- Public REST API and an OAuth MCP server with sending kept behind a separate permission
- Code is public and the web app can be self-hosted with Docker, Kubernetes or major clouds
- The email client is free on web, desktop and iPhone
Weaknesses
- No free tier for the AI assistant on the hosted service, and the trial needs a credit card
- Added license terms make company-wide self-hosting (five or more business users) a paid enterprise license
- Gmail and Outlook only
- Slack, integrations, digests and the notetaker start on the $28 Plus plan
- Several newer features are still early access, and Android lags behind iPhone
Inbox Zero pricing
Email app
$0
- Email client for Gmail and Outlook on web, Mac, Windows and iPhone
- Keyboard shortcuts, split inbox and all accounts in one place
- Team comments on threads
- AI sorting and drafting need a paid plan
Starter
$18
Billed monthly
- Per user, billed annually ($20 billed monthly)
- Sorts and labels every email and drafts replies in your voice
- Cold email blocker, bulk unsubscribe and archive
- Email analytics and pre-meeting briefings
- 7-day free trial
Plus
$28
Billed monthly
- Per user, billed annually ($35 billed monthly)
- 2 email accounts included per user
- AI meeting notetaker and email digests
- Slack and app integrations
- Auto-file attachments and unlimited knowledge base
Professional
$42
Billed monthly
- Per user, billed annually ($50 billed monthly)
- Everything in Plus
- Team-wide analytics
- Priority support and a dedicated onboarding manager
Enterprise
Custom
- SSO and SCIM
- On-premise deployment
- Dedicated account manager
Free tier limits: The email client is free. The AI assistant plans have a 7-day free trial, and a credit card is required to start it.
Note: Prices are per user per month; annual billing saves up to 20%. Plans can be changed at any time with prorated billing, discounts are available for students, nonprofits and open-source projects, and refunds are offered within 14 days of upgrading. Using your own AI provider key means that provider bills you for model usage. Self-hosting is free for personal, educational and research use and for organizations with fewer than five business users; larger organizations need an enterprise license under the repository's license terms.
Technical specs
Available models
Where Inbox Zero excels
Founder or executive inbox triage
Default rules sort every message, cold email and newsletters are archived out of the way, and replies are pre-drafted for the To Reply label, so the morning pass through email becomes reviewing and sending drafts.
Clearing an email backlog
Bulk Unsubscribe and Bulk Archive work through years of senders and categories at once, and the cold email blocker and rules keep the inbox from filling back up.
Developer-controlled email automation
Scoped API keys, webhook actions and an MCP server let you create rules from scripts or let Claude or Cursor draft replies, while self-hosting with your own model keeps mail on infrastructure you run.
Inbox Zero vs. competitors
Inbox Zero vs. Town
Town gives each employee a personal assistant with its own @town.com address that triages Gmail or Outlook, drafts replies, schedules meetings and runs routines across 50+ integrations, with assistants coordinating with each other; it is hosted only and billed in credits. Inbox Zero concentrates on email with plain-English rules, bulk cleanup, reply tracking and a free email client, and can be self-hosted with your own model.
Inbox Zero vs. Lindy
Lindy is a Slack-native AI teammate that works across email, calendar, meetings and more than 1,000 app integrations and MCP servers, with no self-hosted option. Inbox Zero covers a narrower job, running your Gmail or Outlook inbox through editable rules and drafting replies, with public code and a bring-your-own-key option.
Frequently asked questions
What does Inbox Zero do?
Inbox Zero connects to a Gmail or Outlook mailbox and runs rules you describe in plain English. As mail arrives it labels it, archives noise such as marketing and cold email, and pre-drafts replies in your voice for messages that need one. It also tracks threads awaiting replies, bulk-unsubscribes from newsletters, sends meeting briefs, and can be reached from Slack, Microsoft Teams or Telegram. A separate email client is available for web, desktop and iPhone.
How much does Inbox Zero cost?
The email client is free. The AI assistant plans are Starter at $18 per user per month billed annually ($20 monthly), Plus at $28 ($35 monthly) and Professional at $42 ($50 monthly), each with a 7-day free trial. Enterprise pricing for SSO, SCIM and on-premise deployment is custom. Inbox Zero offers discounts for students, nonprofits and open-source projects and refunds within 14 days of upgrading.
Is Inbox Zero open source?
The code for the AI assistant, web app and desktop email client is public on GitHub, and Inbox Zero describes it as open source under AGPL-3.0. The repository's LICENSE adds terms on top of the AGPL: you may not monetize the software, for example by selling access or offering it as a paid service, without written permission, and organizations with five or more business users need an enterprise license. Personal, educational and research use and organizations under five business users are exempt. The iPhone app is not open source.
Can I self-host Inbox Zero?
Yes. The setup CLI (npx @inbox-zero/cli setup, then start) configures and runs Inbox Zero with Docker, and there are guides for Docker on a VPS, Vercel, Kubernetes, AWS and Google Cloud. You supply your own Google or Microsoft OAuth app and an AI provider such as OpenAI, Anthropic, Google, AWS Bedrock, OpenRouter or a local model through Ollama. Check the license terms first if five or more people at your organization will use it.
Can I use my own AI model or API key?
Yes. Inbox Zero covers AI costs by default, but on the hosted service you can enter your own key and model for Anthropic, OpenAI, Azure OpenAI, Google, Groq, Cerebras, OpenRouter or Vercel AI Gateway, and the provider bills you directly. Self-hosted deployments can also use Azure AI Foundry, Google Vertex AI, AWS Bedrock, Ollama and OpenAI-compatible servers such as LM Studio or vLLM.
Does Inbox Zero send emails without asking?
It depends on your rules. By default it drafts replies and leaves them for you to send, and chat and messaging-channel workflows ask for confirmation before high-impact actions such as sending. Rules you create can include send, reply or forward actions, and those run automatically once the rule is enabled, so Inbox Zero recommends testing new rules and reviewing the History tab first. Through MCP, sending requires a separate permission you approve per app.
Does Inbox Zero have an API or MCP server?
Yes. The REST API uses scoped API keys bound to one inbox and covers email statistics, creating and editing rules, and unsubscribing from senders. The MCP server connects ChatGPT, Claude, Cursor or another assistant over OAuth to search and read mail, create drafts, manage rules and read statistics; sending email requires a separate scope.
Is Inbox Zero secure, and is it SOC 2 certified?
Inbox Zero states that it is SOC 2 Type 2 certified and CASA Tier 2 accredited under Google's third-party security assessment, and it runs a trust center at security.getinboxzero.com; these are the company's own statements. It asks for mailbox access to read, organize and draft email, requests calendar or drive access only when you turn on those features, and offers a sensitive-data policy that can redact or block detected credentials and card numbers before content reaches the AI provider. The company says it does not train AI on your data. For full control over where mail is processed, you can self-host it.
Inbox Zero vs Town: what is the difference?
Both connect to Gmail or Outlook to triage mail and draft replies in your voice. Town gives each person a broader workplace assistant with its own email address, routines, 50+ app integrations and assistant-to-assistant collaboration; it has a limited free plan, bills paid plans in credits and is hosted only. Inbox Zero stays focused on the inbox with editable plain-English rules, bulk cleanup tools and a free email client, and its code can be self-hosted with your own model.
Integrations & fit
Alternatives to consider
Town.com, Inc.
Executives, founders, chiefs of staff, EAs, sellers, recruiters and investors whose days run through Gmail or Outlook, a calendar and a CRM, and teams that want each person to have their own assistant that can coordinate with colleagues' assistants and outside contacts while asking before anything is sent
Freemium
Lindy
Individual professionals and small teams who want an AI assistant that works across their actual email, calendar, and CRM without building explicit automation flows
PaidAbout Inbox Zero
Inbox Zero has two parts that work independently. The AI assistant connects to a Gmail, Google Workspace, Outlook or Microsoft 365 mailbox and works in the background: you keep reading mail in Gmail or Outlook while it labels each message (categories and folders on Outlook), archives noisy categories such as marketing and cold email, and leaves a draft reply in your drafts folder for anything marked To Reply. Its behavior comes from rules. Onboarding sets up a default set, and you add your own by describing them in plain English; each rule pairs an AI or static condition with actions such as label, archive, forward, draft or send a reply, add to a digest, call a webhook, create a Todoist task or notify you in Slack, Microsoft Teams or Telegram. A Test tab runs rules against real messages without applying them, a History view shows what fired, and a Fix action lets you explain a wrong match so the rule is updated. Around the rules sit Reply Zero (To Reply and Awaiting Reply tracking with follow-up reminders), Bulk Unsubscribe and Bulk Archive for backlogs, email analytics, calendar-aware scheduling replies and booking links, pre-meeting briefs and, on Plus and above, a meeting notetaker and auto-filing of attachments to Google Drive or OneDrive. The second part, the email client launched on Product Hunt in October 2026 as Inbox Zero Mail, is a keyboard-driven app with a split inbox, several Gmail and Outlook accounts in one place and private team comments on threads; it is free to use, and the AI plans add sorting and drafting inside it. What sets Inbox Zero apart from closed assistants is control: the hosted service lets you bring your own Anthropic, OpenAI, Google, Groq, OpenRouter or other provider key, a REST API and an OAuth MCP server expose rules, drafts and inbox search to scripts and assistants such as Claude, ChatGPT and Cursor, and the whole web app can be self-hosted with Docker and your own model, including local models through Ollama. The tradeoffs are licensing and scope. The repository is AGPL-3.0 with additional terms that forbid monetizing the software without permission and require organizations with five or more business users to buy an enterprise license, so it is not free for company-wide self-hosting. And unlike broader workplace assistants, it stays focused on email and the calendar rather than acting across a long list of business apps.
Updates from Inbox Zero
Inbox Zero launched Inbox Zero Mail, a keyboard-first email client for Gmail and Outlook pitched as an open-source Superhuman alternative. The client is free on web, Mac, Windows and iPhone, brings several accounts into one inbox with private team comments, and adds AI sorting and drafted replies with a paid plan. It was the top product of the day on Product Hunt.
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