openagent.email

Self-hosted email for AI agents. The open-source alternative to AgentMail.

openagent.email · website: openagentemail/website

One docker compose up on your own VPS gives every agent you run unlimited real mailboxes on your own domain — over REST and MCP — with OTP and verification-link extraction built in. No per-inbox pricing, no third party ever seeing your mail.

Quickstart

npx -y @openagentemail/setup

A guided wizard: it checks what you already have, helps you pick a VPS and a domain if you're missing either, and connects your agent clients (Claude Code, Cursor, Kimi Code…) once the server is up.

The manual path needs a VPS with outbound/inbound port 25 open and a domain you control:

git clone https://github.com/openagentemail/openagentemail.git && cd openagentemail
cp .env.example .env   # set DOMAIN, API_KEYS, mailbox password, and NTFY_ADMIN_PASSWORD
docker compose up -d
sudo ./deploy/dns-records.sh   # prints the exact DNS records to create

Then verify everything end to end:

sudo ./deploy/doctor.sh

doctor.sh checks .env permissions; MX, A, SPF, DKIM, and DMARC; PTR; outbound port 25; DNS blocklists; TLS certificates on 465 and 993; and the server-side ntfy verification endpoint. It does not log in over IMAP/SMTP or send a round-trip test. Docker Mailserver can create docker-data/ as root, so use sudo for these two scripts; an EACCES failure prints the same retry instruction instead of pretending the DKIM key is missing.

If no SMTP relay is configured and outbound port 25 is blocked, API queued:true only means the local mailserver accepted the message. It does not mean the recipient received it: Postfix can retain the message in its queue. Treat doctor's outbound-port-25 result as the delivery prerequisite, or configure a relay before relying on direct delivery.

Public TLS with Let's Encrypt (opt-in)

The default docker compose up -d path remains self-signed: it does not start or pull Certbot and does not publish TCP 80. To use a publicly trusted mail certificate, opt in only after mail.$DOMAIN has an A (and, if used, AAAA) record pointing at this host and the firewall permits inbound TCP 80. HTTP-01 cannot create those DNS or firewall prerequisites for you.

In .env, set the following (use a reachable contact address outside this mailserver when possible):

SSL_TYPE=letsencrypt
SSL_DOMAIN=mail.example.com       # exactly mail.$DOMAIN
LETSENCRYPT_EMAIL=admin@example.net  # optional, but recommended

First issue the certificate with the explicitly enabled sidecar; do not start the mailserver in letsencrypt mode before this succeeds:

docker compose --profile letsencrypt-bootstrap up -d certbot-bootstrap
docker compose logs -f certbot-bootstrap
# Wait for “Successfully received certificate”, then confirm:
docker compose --profile letsencrypt-bootstrap run --rm --no-deps \
  --entrypoint ls certbot-bootstrap -l \
  /etc/letsencrypt/live/mail.example.com/fullchain.pem \
  /etc/letsencrypt/live/mail.example.com/privkey.pem

This temporary container reads the shared certificate volume, so confirmation still works after the one-shot bootstrap has stopped.

If first issuance fails, Certbot stops instead of retrying the ACME request in a tight loop. Correct the DNS/port-80/domain prerequisite, then explicitly run the same docker compose --profile letsencrypt-bootstrap up -d certbot-bootstrap command again.

The entire /etc/letsencrypt tree is a persistent named volume shared with the mailserver read-only: Certbot's live/ files are symlinks into archive/, so mounting only live/ is incorrect. Once the first certificate exists, start the full opt-in stack and verify the public endpoints. Do not enable letsencrypt-bootstrap and letsencrypt together: both publish host TCP 80.

docker compose --profile letsencrypt up -d
./deploy/doctor.sh
openssl s_client -connect mail.example.com:465 -servername mail.example.com </dev/null \
  2>/dev/null | openssl x509 -noout -issuer -subject -dates
openssl s_client -connect mail.example.com:993 -servername mail.example.com </dev/null \
  2>/dev/null | openssl x509 -noout -issuer -subject -dates

After bootstrap, the renewal sidecar runs renew every 12 hours and restarts with Docker. docker-mailserver's change-detection service watches SSL_TYPE=letsencrypt certificate updates and reloads Postfix and Dovecot, so renewed certificates take effect on 465/993 without a manual container restart. Keep the letsencrypt profile enabled for normal operation. If it is omitted, the sidecars and TCP 80 are absent and the original self-signed path is unchanged.

Create an identity and hand your agent its scoped token (shown once):

curl -X POST http://localhost:3100/v1/identities \
  -H "Authorization: Bearer $API_KEY" -H "Content-Type: application/json" \
  -d '{"name":"signup-bot","scopes":["read:messages"]}'
# → 201 {"address":"fox-k7d2@example.com","name":"signup-bot","token":"oa_…","scopes":["read:messages"]}

The API binds to 127.0.0.1 by default — reach it from other hosts over an SSH tunnel or a TLS proxy: docs/security.md.

Paths are exact: call /v1/notify, not /v1/notify/ — a trailing slash returns a plain 404 rather than the API error format.

Using your own mail server

Already have a mail provider for your domain? Run the API by itself with compose.api-only.yaml, connected to that provider's catch-all mailbox. The external mail server guide covers the required catch-all setup, Portainer deployment, SMTP sender limits, and TLS certificate verification.

The standalone default project name is openagentemail. If the full compose.yaml stack also runs on the same host, the API-only stack must not share that default project: give it an explicitly different -p value or COMPOSE_PROJECT_NAME so the two stacks cannot adopt each other's resources.

To run multiple API-only instances on one host, give every instance its own environment file, unique Compose project, and host API_PORT. The API always listens on port 3100 inside its container; API_PORT changes only the host-side mapping. For example:

mkdir -p ../oae-api-only-env
cp .env.api-only.example ../oae-api-only-env/alpha.env
cp .env.api-only.example ../oae-api-only-env/beta.env
chmod 600 ../oae-api-only-env/*.env
# Set API_PORT=3100 in alpha.env and API_PORT=3101 in beta.env.
# Generate separate API_KEYS and TASK_SIGNING_SECRET values in each file.

docker compose -p oae-alpha --env-file ../oae-api-only-env/alpha.env -f compose.api-only.yaml up -d
docker compose -p oae-beta  --env-file ../oae-api-only-env/beta.env  -f compose.api-only.yaml up -d

You may set a unique COMPOSE_PROJECT_NAME for each command instead of using -p. The project names make Compose generate distinct container names and project-scoped named volumes (for example oae-alpha_api-data and oae-beta_api-data). Do not reuse a project name or API_PORT between the two instances. Each instance must have independently generated API_KEYS and TASK_SIGNING_SECRET values; configure its IMAP and SMTP credentials for that instance's intended mailbox/provider boundary as well. Keep these populated environment files outside the repository, as in the example above.

Read mail in a browser

Open http://localhost:3100/ui and paste an admin or identity API token. The built-in dashboard lists the addresses the token may access, shows Inbox / All Mail (IMAP) and Sent (API/MCP send audit for 30 days; direct SMTP is not listed) with cursor paging, extracts verification codes and links at the top of a message, offers Rendered (isolated HTML iframe), Plain text, or Source views, and can mark messages read or unread. Source is fetched on demand from a size-capped no-store endpoint and never injected as HTML. Scheduled and Trash are omitted until the backend can serve them. Admin sessions can also create identities (with custom address prefixes), rotate tokens, and delete identities directly from the overview table.