# Startup Mail

> Startup Mail is a focused custom-domain email service for small companies, software, and agents. It combines a human web inbox with forwarding, explicit team access, a REST API, TypeScript SDK, signed webhooks, and MCP.

## Instructions for AI agents

- Fetch any documentation page as clean Markdown by appending `.md` to its canonical URL.
- Send `Accept: text/markdown` to a documentation URL for the same Markdown representation.
- Use this file to discover pages, then fetch only the pages relevant to the task.
- Startup Mail permits direct conversations and requested transactional email; it does not permit newsletters, campaigns, or cold outreach.
- The public REST API base is `https://api.startupmail.dev/v1`.
- The Streamable HTTP MCP endpoint is `https://api.startupmail.dev/mcp`.

## Start here

- [Documentation](https://startupmail.dev/docs.md): Set up a company inbox for people, products, and agents—without adopting the rest of an office suite.
- [Quickstart](https://startupmail.dev/docs/quickstart.md): Go from a domain you own to a working two-way mailbox in about ten minutes.
- [How Startup Mail works](https://startupmail.dev/docs/how-it-works.md): Understand the route from DNS to inbox, forwarding destination, webhook, API, or agent.

## Use Startup Mail

- [Domains and DNS](https://startupmail.dev/docs/domains.md): Connect a domain, publish the four required record types, and diagnose verification.
- [Mailboxes](https://startupmail.dev/docs/mailboxes.md): Create company addresses and choose who can read, send, and manage each one.
- [Use the web inbox](https://startupmail.dev/docs/web-inbox.md): Read, search, organize, compose, and reply from Startup Mail’s focused mail surface.
- [Forward to Gmail or Outlook](https://startupmail.dev/docs/forwarding.md): Receive company mail in an inbox you already use and reply through a protected relay.
- [Teams and private access](https://startupmail.dev/docs/team-access.md): Invite people, assign workspace roles, and grant private mailbox access separately.
- [Send and reply](https://startupmail.dev/docs/sending.md): Send expected email from the web inbox or developer interfaces and follow delivery state.
- [Receive mail and read threads](https://startupmail.dev/docs/receiving.md): Work with incoming messages, labels, complete threads, and real-time notifications.
- [Attachments](https://startupmail.dev/docs/attachments.md): Upload files before sending and download inbound files with mailbox authorization.

## Build with it

- [API overview](https://startupmail.dev/docs/api-overview.md): Authenticate to the v1 REST API, choose scopes, and handle responses and errors.
- [API reference](https://startupmail.dev/docs/api-reference.md): The complete public endpoint surface for mailboxes, threads, messages, attachments, and webhooks.
- [TypeScript SDK](https://startupmail.dev/docs/sdk.md): Use the typed Startup Mail client to work with mailboxes, threads, messages, files, and webhooks.
- [Webhooks](https://startupmail.dev/docs/webhooks.md): Receive signed, retried HTTPS events when mail or domain state changes.
- [MCP for agents](https://startupmail.dev/docs/mcp.md): Give an agent narrowly scoped tools for listing, reading, sending, and replying to mailbox conversations.

## Operate safely

- [Usage and limits](https://startupmail.dev/docs/usage-limits.md): Understand email events, storage, recipient and attachment limits, and workspace safety caps.
- [Security and privacy](https://startupmail.dev/docs/security.md): How mailbox access, secret storage, HTML isolation, webhook signing, and delivery controls fit together.
- [Troubleshooting](https://startupmail.dev/docs/troubleshooting.md): Resolve DNS, receiving, sending, forwarding, API, webhook, and access problems.

## Additional resources

- [Product website](https://startupmail.dev/)
- [Acceptable use policy](https://startupmail.dev/acceptable-use)
- [TypeScript SDK repository](https://github.com/gustavhartz/startupmail/tree/main/packages/sdk)
- [Source repository](https://github.com/gustavhartz/startupmail)
- [Full documentation bundle](https://startupmail.dev/llms-full.txt)