docs/deployments/services/email/mailcow.md

---

tags:
- Mailcow
- Email
- Docker

---

## Purpose
The purpose of this document is to illustrate how to deploy Mailcow in a dockerized format.

!!! note "Assumptions"
    It is assumed that you are deploying Mailcow into an existing Ubuntu Server environment.  If you are using a different operating system, refer to the [official documentation](https://docs.mailcow.email/getstarted/install/).

### Setting Up Docker
Go ahead and set up docker and docker-compose with the following commands:

```bash
sudo su # (1)
curl -sSL https://get.docker.com/ | CHANNEL=stable sh # (2)
apt install docker-compose-plugin # (3)
systemctl enable --now docker # (4)
```

1. Make yourself root.
2. Install `Docker`
3. Install `Docker-Compose`
4. Make docker run automatically when the server is booted.

### Download and Deploy Mailcow
Run the following commands to pull down the mailcow deployment files and install them with docker.  Go get a cup of coffee as the `docker compose pull` command may take a while to run.

!!! note "Potential `Docker Compose` Issues"
    If you run the `docker-compose pull` command and it fails for some reason, change the command to `docker compose pull` instead.  This is just the difference between the plugin version of compose versus the standalone version.  Both will have the same result.

```bash
cd /opt
git clone https://github.com/mailcow/mailcow-dockerized
cd mailcow-dockerized
./generate_config.sh # (1)
docker-compose pull # (2)
docker-compose up -d
```

1. Generate a configuration file. Use a FQDN (`host.domain.tld`) as hostname when asked.
2. If you get an error about the ports of the `nginx-mailcow` service in the `docker-compose.yml` stack, change the ports for that service as follows:

   ```yaml
   ports:
     - "${HTTPS_BIND:-0.0.0.0}:${HTTPS_PORT:-443}:${HTTPS_PORT:-443}"
     - "${HTTP_BIND:-0.0.0.0}:${HTTP_PORT:-80}:${HTTP_PORT:-80}"
   ```

### Firewall / NAT Configuration
Forward Mailcow service ports as follows:

```text
WAN :80  -> Traefik :80
WAN :443 -> Traefik :443

WAN :25   -> Mailcow :25
WAN :465  -> Mailcow :465
WAN :587  -> Mailcow :587
WAN :993  -> Mailcow :993
WAN :995  -> Mailcow :995
WAN :110  -> Mailcow :110
WAN :143  -> Mailcow :143
WAN :4190 -> Mailcow :4190
```

Mail protocol ports should be sent directly to the Mailcow server. Traefik should not terminate or proxy the SMTP, SMTPS, Submission, IMAP, IMAPS, POP3, POP3S, or ManageSieve ports.

### Reverse-Proxy Configuration
For the purposes of this document, it will be assumed that you are deploying Mailcow behind Traefik for web traffic only. Traefik should pass HTTPS through transparently, allowing Mailcow to manage and serve its own certificates.

You can use the following dynamic configuration file to achieve this:

```yaml title="/srv/containers/traefik/config/dynamic/mail.bunny-lab.io.yml"
# =====================================================================
# Mailcow / Traefik Dynamic Configuration
# Hostname: mail.bunny-lab.io
#
# Mailcow owns certificates.
# Traefik forwards HTTP and passes HTTPS through.
# Mail protocol ports are handled directly by pfSense -> Mailcow.
# =====================================================================

http:
  routers:
    mailcow-http:
      entryPoints:
        - web
      rule: Host(`mail.bunny-lab.io`)
      service: mailcow-http
      priority: 100

  services:
    mailcow-http:
      loadBalancer:
        passHostHeader: true
        servers:
          - url: "http://192.168.3.61:80"

tcp:
  routers:
    mailcow-https-passthrough:
      entryPoints:
        - websecure
      rule: HostSNI(`mail.bunny-lab.io`)
      service: mailcow-https
      tls:
        passthrough: true

  services:
    mailcow-https:
      loadBalancer:
        servers:
          - address: "192.168.3.61:443"
```

### Traefik-Specific Configuration
Traefik only needs the standard HTTP and HTTPS entrypoints for Mailcow web traffic. Mail protocol ports should not be exposed through Traefik if the firewall is forwarding those ports directly to Mailcow.

```yaml
#Entrypoints
- "--entrypoints.web.address=:80"
- "--entrypoints.websecure.address=:443"

#Ports
- "80:80"
- "443:443"
```

Do not add Mailcow mail protocol entrypoints or port bindings to Traefik unless you intentionally want Traefik to proxy those ports.

### Certificate Validation
Mailcow should manage and serve the certificate for `mail.bunny-lab.io`.
To verify the active Mailcow certificate on disk, run the following on the Mailcow server:

```bash
cd /opt/mailcow-dockerized

openssl x509 \
  -in /opt/mailcow-dockerized/data/assets/ssl/cert.pem \
  -noout -subject -issuer -dates -serial -fingerprint -sha256
```

If the certificate has renewed but services are still presenting an old certificate, restart the Mailcow services that serve TLS:

```bash
cd /opt/mailcow-dockerized
docker compose restart postfix-mailcow dovecot-mailcow nginx-mailcow
```

### Login to Mailcow
At this point, the Mailcow server has been deployed so you can log into it.

* **Administrators**: `https://${MAILCOW_HOSTNAME}/admin` (Username: `admin` | Password: `moohoo`)
* **Regular Mailbox Users**: `https://${MAILCOW_HOSTNAME}` (*FQDN only*)

### Mail-Client Considerations
You need to ensure that you generate an app password if you have MFA enabled within Mailcow.  (MFA is non-functional in Roundcube/SoGo, you set it up via Mailcow itself).  You can access it via the Mailcow configuration page: https://mail.bunny-lab.io/user, then look for the "**App Passwords**" tab.

### Running Updates
If you want to run updates, just SSH into the server, and navigate to `/opt/mailcow-dockerized` and run `./update.sh`.  I recommend avoiding the IPv6 implementation section.  Be patient, and the upgrade will be fully-automated.