Every email API can send. Almost none help you with the hard part — receiving and understanding mail without hand-parsing MIME or babysitting a mailbox. Inboundr is the inbox side of email, built to be operated by code. Point a domain at Inboundr and every address on it becomes a parsed, threaded inbox your software can read — over a webhook, a REST call, or a native MCP tool your AI agent drives directly.
Agent-native, not agent-compatible. Reading a thread isn’t an afterthought bolted onto a receive-only API — it’s a first-class MCP tool, same as filtering with Shield. An agent can run its inbox without a line of glue code.

​
One inbox, three ways in

Inboundr sits between your code and everyone who mails it. Mail from any number of senders funnels into one parsed, threaded inbox, which your software reads over whichever of the three surfaces suits it — mix and match freely, since a store-only inbox is always readable even while it also fires webhooks. Three senders — customer, vendor, alerts — funnelling through Inboundr, then out to a webhook, the REST API, and an MCP agent Every address on your domain accepts mail without being created first, and each message arrives parsed, threaded, and attributed to a conversation — see Receiving email.

Webhooks

A signed email.received event, the moment mail lands. Best for servers and automations.

REST API

Poll and search a small, predictable JSON API. Best for scripts and backends.

MCP

List, read, and thread as tools, plus filter with Shield. Best for agents that act on demand.

​
What you get that raw email doesn’t

Parsed, not raw

Clean JSON — text and HTML bodies, attachment metadata, and SPF/DKIM/spam verdicts — instead of a MIME blob you have to decode yourself.

Conversations, not messages

Inboundr threads inbound mail automatically using standard headers, so you read a whole exchange in one call instead of stitching messages together.

Your domain, your addresses

Bring your own domain and keep full ownership. Catch-all means every address works without pre-creating it.

Delivery you can trust

Signed webhooks, exponential-backoff retries, and every attempt recorded in the console.

​
The shape of an integration

Most Inboundr projects come down to the same loop — the agent inbox loop:
1

Mail arrives

Someone emails an address on your verified domain. Inboundr parses it and stores it on a thread.
2

Your code reads it

A webhook fires, or your agent calls list_emails / get_thread.
3

Your code acts on it

Route it, file it, alert on it — or filter it before it ever lands with a Shield rule.
Everything else in these docs is a detail of that loop.

​
Start here

Quickstart

Domain to first parsed email in a few minutes.

How Inboundr works

The mental model behind domains, routing, and inboxes.

Build an email agent

Wire an agent to its own inbox over MCP.

API reference

Every endpoint, parameter, and response.