Your agents need email. We handle the infrastructure.

MailboxKit gives any AI agent a real email address with send, receive, and reply capabilities. Your agent installs an NPM package or MCP server and starts emailing in under a minute. You manage billing and domains from the dashboard.

Why your agents need email

Email is still how the world communicates. Your agents should be part of that.

Autonomous communication

Your agent can send status updates, collect information, and follow up — all through email. No human in the loop required.

Real email identity

Not a forwarding alias. Your agent gets a real address (or uses your custom domain) that recipients can reply to.

Full conversation context

Threading, quoted content parsing, and read tracking. Your agent maintains context across an entire email conversation.

How it works

Four steps from signup to your agent sending email.

1

Sign up and get an API key

Create an account, or your agent self-registers with your email via the API.

2

Install the SDK or MCP server

npm install mailboxkit — or add the MCP server to your agent's config.

3

Your agent sends its first email

One API call and your agent has a real email address, ready to send and receive.

4

You manage the rest

Billing, custom domains, and webhooks — all from the dashboard. Your agent handles the email.

How agents integrate

Three ways for your agent to connect. Pick whichever fits your stack.

Node.js SDK

Import and call. Handles auth, retries, and types.

npm install mailboxkit

MCP Server

Add to your agent's MCP config. No code needed.

npx mailboxkit-mcp@latest

REST API

Plain HTTP from any language. Bearer token auth.

curl -H "Authorization: Bearer $KEY" \
  https://mailboxkit.com/api/v1/inboxes

What's included

Every feature, every account. No tiers, no gating.

Unlimited inboxes
Unlimited API keys
Custom domains with DKIM/SPF/DMARC
Inbound email processing
Webhook notifications (9 event types)
Conversation threading
Attachment support
Email open tracking
Sandbox mode for testing
Idempotency for reliability
extracted_text for clean replies
REST API + Node.js SDK + MCP Server

Simple pricing

$0.002/ email
$0.001/ attachment

$1.00 free credit on signup (500 emails)

No subscriptions, no monthly minimums

View pricing details →

Get started in under a minute

$1.00 free credit. No credit card required. Your agent is sending email in 60 seconds.