MailKite Server

Spec sheet

Purpose

MailKite Server is an open-source email server for apps and AI agents.Read 11 Oct 2026 · mailkite.dev

Deployment

The project says it runs on Node.js 22.5 or later and documents Docker Compose, VPS, Fly.io, and Railway deployments.Read 11 Oct 2026 · mailkite.dev

API

The self-hosted API supports JSON send and receive through /v1/send, /v1/send/batch, /v1/me, and /api/messages.Read 11 Oct 2026 · mailkite.dev

Integrations

MailKite lists official SDKs for Node.js, Python, Ruby, Go, PHP, Java, C#, and Rust, plus a CLI, an MCP server, and SMTP relay integrations.Read 11 Oct 2026 · mailkite.dev

Security

Server components use HMAC-authenticated HTTP endpoints, and inbound webhook deliveries are signed and retried.Read 11 Oct 2026 · mailkite.dev

Support

The self-hosted server page directs users to GitHub discussions and setup documentation; it describes human support as a MailKite Cloud offering.Read 11 Oct 2026 · mailkite.dev

License

The server components are licensed under AGPL-3.0.Read 11 Oct 2026 · mailkite.dev

Headquarters

Sheridan, Wyoming, USARead 28 Sep 2026 · mailkite.dev

Company

MailKite is a business name of SendHub LLC, whose listed address is 30 N Gould St #59709, Sheridan, Wyoming 82801, USA.Read 11 Oct 2026 · mailkite.dev

Maker

The site identifies SendHub LLC, doing business as MailKite, and gives its address as 30 N Gould St #59709, Sheridan, WY 82801, USA.Read 11 Oct 2026 · mailkite.dev

API limits

The maker says templates, scheduling, attachments, tracking, and other hosted-only features are not yet part of the self-hosted API surface.Read 11 Oct 2026 · mailkite.dev

Backend

The reference backend is one Node process using node:sqlite with zero npm dependencies.Read 11 Oct 2026 · mailkite.dev

Components

The stack includes Haraka SMTP MX and submission edges, an IMAP server, a SQLite reference backend, and a web console.Read 11 Oct 2026 · mailkite.dev

IMAP

The IMAP4 server uses implicit TLS on port 993 and is described as read-mostly INBOX and Sent.Read 11 Oct 2026 · mailkite.dev

IMAP limitations

The maker describes its IMAP support as read-mostly INBOX and Sent, without full IMAP or JMAP features such as folders, server-side rules, and ManageSieve.Read 11 Oct 2026 · mailkite.dev

Inbound delivery

Inbound messages can be delivered to the backend as signed webhooks with retries, or accessed through REST or IMAP.Read 11 Oct 2026 · mailkite.dev

Inbound mail

The MX edge checks recipients and sends raw messages to the backend as signed webhooks.Read 11 Oct 2026 · mailkite.dev

Intended use

The project is aimed at getting email into application code; its page says it is not intended as a full human mailbox service with webmail, calendars, and quotas.Read 11 Oct 2026 · mailkite.dev

Notable limits

The self-hosted API does not yet claim full Cloud API parity; templates, scheduling, attachments, and tracking are listed as hosted-only features.Read 11 Oct 2026 · mailkite.dev

Outbound mail

The submission edge supports SMTP AUTH on ports 587 and 465 and signs mail with DKIM.Read 11 Oct 2026 · mailkite.dev

SDKs

The official Node or TypeScript client can target a self-hosted server by setting its base URL.Read 11 Oct 2026 · mailkite.dev

Storage and dependencies

The reference backend uses Node’s built-in SQLite module and has zero npm dependencies.Read 11 Oct 2026 · mailkite.dev

Use case

The maker positions the server for getting email into application code and says it is not intended to provide human mailboxes with webmail, calendars, and quotas.Read 11 Oct 2026 · mailkite.dev

Plans and prices

Every MailKite Server plan and price →

Where Specifiction places it

• Email APIs#8 of 318.4