Open-source email infrastructure for AI agents

Your agents need mailboxes. You should own the post office.

One Cloudflare account, one mail domain, many agent mailboxes. Receive, poll, send, and reply without handing message data to a hosted control plane.

Read the setup guide Explore the code

Built only for Cloudflare. No hosted control plane.

A red and black post-office sorting wall routing envelopes through transparent message channels — Every mailbox is an explicit address. Unknown recipients are rejected.

Operator-ownedRuns in your Cloudflare account

Multiple mailboxesOne custom mail domain

Pull-basedREST, CLI, and MCP

Open sourceInspect every boundary

MIT-licensed infrastructure

Open source. Host it yourself.

Clone the repository, provision the Cloudflare resources in your own account, and keep the Worker, database, objects, queues, tokens, and message data under your control. Agent Post Office has no hosted service to subscribe to and no control plane to trust.

Inspect the open-source repository

A self-contained red and black mail-processing cabinet installed inside a bright operator-owned sorting room — The deployment boundary is a Cloudflare account you operate.

Create many addresses. Poll one domain-wide feed.

Give research, support, operations, or any other agent a durable address on the domain you control. Active mailboxes receive mail. Disabled and unknown addresses do not.

Messages stay unprocessed until an agent acknowledges them. Sending and replies use explicit scopes and idempotency keys, so automation has visible boundaries.

Mail moves on your agent’s schedule.

No inbound webhook is required. Agents initiate every API connection.

Receive
Cloudflare Email Routing invokes the Worker for the exact envelope recipient.
Store and parse
Raw MIME goes to private R2 before an ID-only task enters Queues.
Poll and acknowledge
Agents read a unified feed and explicitly mark completed messages processed.
Send or reply
Cloudflare Email Sending handles transactional mail with scoped authorization.

Built only for Cloudflare

Six services. One operator-owned boundary.

There is no Agent Post Office account, hosted database, or message relay outside your deployment.

Email Routing: Receives inbound SMTP and invokes the Email Worker.
Workers: Runs ingestion, REST endpoints, and Queue consumers.
D1: Stores mailbox state, message indexes, and hashed token metadata.
R2: Keeps raw MIME, complete bodies, and attachments private.
Queues: Parses messages and retries deletion work without carrying MIME.
Email Sending: Sends transactional messages and threaded replies.

Bring your own Cloudflare account

Fewer copies. A boundary you operate.

Agent Post Office does not run a hosted control plane, database, or message relay. Your deployment receives mail directly into the Cloudflare resources you provision, so there is no second Agent Post Office service holding another copy.

Private message storage

Raw MIME, complete bodies, and attachments stay in your private R2 bucket. Downloads force attachment handling, no-store caching, and content sniffing protection.

Credentials stay local

Only token hashes enter D1. Raw bearer tokens remain in the operating-system credential store or a protected process environment, never in URLs.

Hostile content stays untrusted

HTML is not rendered and attachments are not opened automatically. MCP output labels message content as untrusted and exposes attachment metadata before bytes.

Content-minimal logging

Message content is not logged by default. Subjects, attachments, tokens, and raw addresses are also excluded from default application logs.

One red mail intake tray connected by blue routes to ten separate black agent mailbox drawers — One domain-wide intake, many explicit agent mailboxes.

One domain does the sorting.

Create a durable address for each agent without provisioning another vendor inbox. Mail arrives through one routing boundary, then remains isolated by mailbox identity, token scope, and explicit acknowledgement.

Cloudflare requirements

Bring one domain and your Cloudflare account.

Workers Paid account ($5/month) A Workers Paid account is required for sending email to arbitrary recipients through Cloudflare Email Sending.

A domain on Cloudflare DNS Required for Email Routing, mail authentication records, and your agent addresses.

Your own deployment Agent Post Office is free and open source. You install and operate the Worker, D1, R2, and Queues resources.

Run the post office where your mail already lives.

Start with the architecture, inspect the security boundaries, then deploy deliberately.

View Agent Post Office on GitHub Read the security model