LambdaMail/docs/DEPLOYMENT.md

Deploying LambdaMail on Coolify

This is the order things have to happen in. Several steps depend on DNS propagation or on your provider, so read the whole page before starting — a couple of them are worth kicking off early.

Before anything else

Three prerequisites are not automatable, and without them the deployment will come up but mail will not work. Start them now, because two involve waiting on somebody else.

1. Outbound port 25

Most providers block it by default — AWS, GCP, Azure, Oracle, Vultr, and DigitalOcean on newer accounts. Open a support ticket asking for outbound SMTP to be unblocked, and say what the host is for.

If the answer is no, LambdaMail can still send through a relay: set RELAY_HOST and friends, and the relay is added to the published SPF record automatically. Receiving is unaffected either way.

2. Reverse DNS (PTR)

The PTR for your public IPv4 must resolve to PRIMARY_MAIL_HOST, and that name must resolve back to the same address. This is called FCrDNS, and Gmail and Outlook will refuse or spam-folder mail without it.

The PTR is set by whoever owns the IP block — your VPS provider, not Cloudflare. It is usually a field in the server's control panel.

dig -x 203.0.113.10 +short        # must print mail.example.com.
dig mail.example.com +short       # must print 203.0.113.10

3. DNSSEC — only if you want DANE

Signing the zone is a prerequisite for DANE. It is enabled in the Cloudflare dashboard and needs a DS record published at your registrar, which is manual.

Skip this for a first deployment. DANE stays off under TLS_MODE=traefik anyway, and turning it on without understanding the rollover is the single most effective way to make every validating MTA reject your mail permanently.

IPv6

Either configure it properly — AAAA record, matching PTR, and covered by SPF — or leave PUBLIC_IPV6 empty. Half-configured IPv6 is a common cause of rejection, and empty is a safe answer.

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Step 1 — Point DNS at the host

Two records must exist before the first deploy, because Coolify's proxy needs them to obtain certificates:

Type	Name	Value
A	mail	your public IPv4, DNS only, not proxied
A/CNAME	mta-sts	the same host (may be proxied)

The mail record must not be behind Cloudflare's proxy. SMTP is not HTTP; proxying it breaks the mail ports and hides your real address from the certificate challenge.

The rest of the 13 records are created by the service once you give it a Cloudflare token, or you can add them by hand later.

Step 2 — Create the application in Coolify

1. New Resource → Docker Compose, pointed at this repository.
2. Coolify will read docker-compose.yaml. Leave the compose file alone; all configuration is environment.
3. Under Environment Variables, paste the contents of .env.production.example and replace every value marked CHANGE.

Generate each secret separately:

openssl rand -base64 36

LAMBDAMAIL_MASTER_KEY deserves particular care. It encrypts every DKIM private key, TOTP secret and provider token in the database. Store a copy somewhere other than the database backup. If you lose it, those secrets are unrecoverable and you will be reissuing DKIM keys and re-enrolling every user's two-factor.

Ports

Coolify does not map mail ports for you. In the service settings, make sure the host publishes:

25, 465, 587      SMTP
143, 993          IMAP
110, 995          POP3
4190              ManageSieve

These are already declared in docker-compose.yaml; what matters is that the VPS firewall allows them inbound.

The proxy network

The compose file joins Coolify's proxy network, named coolify by default. If yours differs, set COOLIFY_PROXY_NETWORK.

Step 3 — Deploy and check the preflight

Deploy, then run the diagnostics from the host:

docker compose run --rm --entrypoint /app/lambdamail-protocols protocols preflight

It reports outbound port 25, PTR and FCrDNS, whether your IP is on Spamhaus, SpamCop or SORBS, the Cloudflare token's scope, and whether a certificate exists for the mail host. Fix anything it flags before going further — particularly an RBL listing, which will not fix itself.

Step 4 — Create the first administrator

Nothing else creates a mailbox, so without this there is no way into the console:

make create-admin EMAIL=you@example.com PASSWORD='a long passphrase'

This creates the domain if needed, the mailbox as SUPER_ADMIN, its standard folders, and the four system aliases (postmaster@, abuse@, dmarc@, tlsrpt@) that the published DNS records point at.

Then sign in at https://<WEBMAIL_HOST>/, which opens the mail client.

An account that may administer the server gets an Admin console link in the webmail sidebar. Following it asks for the password and second factor again, because the console is a separate audience — being signed in to webmail is never enough on its own.

If the account has no second factor yet, the admin sign-in enrols one on the spot: it shows a QR code to scan, takes the first code back, and hands over the recovery codes. There is no need to visit another screen first, and no way to end up locked out of the console for want of a factor you could not reach.

Leaving the console needs nothing — the webmail session was never given up.

Step 5 — DNS records

With a Cloudflare token set, the service reconciles the zone on start and every six hours after that. Watch it:

docker compose logs -f protocols | grep "DNS reconcile"

It is idempotent, and it never deletes records it did not create — anything unexpected is reported as a conflict rather than overwritten.

Without a token, add the records by hand. The admin console's Domains page lists what is expected.

Step 6 — Verify

Send mail to a Gmail address and check the headers show spf=pass, dkim=pass, dmarc=pass. Then run a round trip through mail-tester.com and read every point it deducts.

A first deployment will usually be short a few points until the DNS records have propagated and the IP has some sending history.

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Upgrading

Images are published to GHCR for linux/amd64 and linux/arm64 on every merge to main.

docker compose pull
docker compose up -d

Deploys pull the images CI published rather than building on the server; docker-compose.build.yaml is the overlay local development uses to build from source instead.

Migrations run automatically on start, before the services that depend on them. Pin IMAGE_TAG to a sha- tag rather than leaving it on latest. Not only for rollback: docker compose up does not re-pull a tag it already has locally, so a deployment left on latest will happily keep running the image it pulled the first time while reporting success. An immutable tag changes on every release, which is what forces the pull.

IMAGE_TAG=sha-<full commit sha>

The tags are published by release.yml; docker buildx imagetools inspect ghcr.io/<owner>/lambdamail/webmail:latest shows what latest currently points at.

Pinning has a second edge: bump it on every release. A pinned tag is an instruction to run that image, so a deploy triggered without changing it re-pulls the same old build and succeeds — the UI simply does not change. Redeploying with "ignore cache" does not help, because that clears the build cache and nothing here is built on the server; the tag being requested is still the old one. The two failure modes are mirror images: latest never updates because Docker already has it, and a stale pin never updates because you asked for it by name.

So a release is two steps, not one:

# 1. point the tag at the new commit
IMAGE_TAG=sha-$(git rev-parse HEAD)
# 2. then deploy

Confirm which one is actually serving before believing a green deployment:

curl -s https://<WEBMAIL_HOST>/user/login | grep -o '/_next/static/css/[a-z0-9]*\.css'

The asset fingerprint changes with every build. If it did not move, the old image is still running whatever the deployment log said.

Troubleshooting

The web UI is up but nothing can log in. The auth service refuses to start without a JWT_SECRET of at least 32 characters. docker compose logs auth will say so.

Mail is accepted but never arrives. Check docker compose logs -f protocols for the delivery worker. A 4.7.5 deferral means the destination published a TLS policy that could not be satisfied — that is deliberate; the message is retried rather than sent in the clear.

/health returns X-LambdaMail-Health: degraded. The stack is running but a certificate needs attention: usually no certificate exists for PRIMARY_MAIL_HOST because no router was declared for it, or one is expiring within 24 hours. The body says which.

Everything is fine but Gmail still spam-folders you. That is reputation, not configuration. A new IP has none. Send low volumes to engaged recipients first and watch the DMARC reports in the admin console.