Step 1 – Verify Mailcow Works

Your server’s IP address and root password are shown in the Server Information section on the Overview tab of your server in the client portal. The application settings you entered when ordering, passwords included, are shown in the Mailcow Credentials card on the same tab. Open https://your.server.ip in a browser. Your server gets a browser-trusted Let’s Encrypt certificate for its IP address during setup, so the page opens without a warning. If the server is not reachable from the internet on port 80 (for example, behind a router), the certificate cannot be issued and the browser shows a warning for a self-signed certificate – in that case proceed to the site; once your mail domain points to the server, Mailcow issues a certificate for it automatically.

First minutes after creation. Setup takes one to two minutes after the server starts, and the client portal shows the server as ready when it finishes. Until your admin password is applied and the certificate is issued, the web interface is not reachable from outside (the browser reports that the connection was refused) – this keeps the vendor’s default admin password from being used by anyone. If the page does not open yet, wait a minute and reload.

The administrator logs in at a separate address – open https://your.server.ip/admin and enter the admin credentials:

• Username: admin
• Password: the Admin Password you entered during the order

Important: The main page https://your.server.ip is the login for mailbox users and asks for an email address. The domain you entered during the order is the mail domain of the server, not a login. The admin address is also shown when you connect via SSH and saved in /root/.mailcow_credentials.

If you see the Mailcow admin dashboard, everything is working correctly.

If you placed the server behind a VyOS router on a private network, forward ports 22 (SSH), 25 (SMTP), 80 (HTTP), 443 (HTTPS), 587 (Submission), 993 (IMAP) and 995 (POP3) to the server on the router’s Configuration tab (Port forwarding). A mail server must be reachable from the internet to send and receive email. Behind the router your mail leaves from the router’s public address: use that address in the A record of your mail host and in the PTR record.

Firewall. If you turn on the Firewall for this server in the client portal, allow incoming TCP port 80 in its rules, along with 443 (HTTPS) and the mail ports listed above. Certificates renew over port 80 – the IP certificate every few days – and without that rule the certificate expires and the browser starts showing a warning.

Step 2 – Configure DNS Records

Proper DNS configuration is critical for email delivery. Without correct records, your emails will be rejected or marked as spam. Go to your domain registrar’s DNS settings and add the following records (replace your.server.ip with your actual server IP and example.com with your domain):

DKIM record: After logging in to the admin panel, go to Configuration → ARC/DKIM keys to get the DKIM key. Then add:

Reverse DNS (PTR record): Contact support to set the PTR record for your server IP to mail.example.com. This is required for reliable email delivery.

DNS changes usually take a few minutes, but can take up to 24 hours. You can check the status at dnschecker.org.

Step 3 – Create Mailboxes

In the admin panel:

1. Go to E-Mail → Mailboxes
2. Click Add mailbox
3. Enter the username (e.g. info), set a password and click Add
4. The new mailbox (e.g. info@example.com) is ready to use

Users can access webmail (SOGo) at https://your.server.ip/SOGo – log in with the full email address and mailbox password.

SSL with Let’s Encrypt

Mailcow has built-in Let’s Encrypt support. Once your A record (mail.example.com) points to the server and DNS has propagated, ensure SKIP_LETS_ENCRYPT=n in mailcow.conf and restart:

cd /opt/mailcow-dockerized
docker compose down && docker compose up -d

Mailcow will automatically obtain and renew the certificate.

Email Client Configuration

To connect an email client (Outlook, Thunderbird, mobile), use these settings:

Username is the full email address (e.g. info@example.com). If you configured autodiscover and autoconfig DNS records, most email clients will detect these settings automatically.

Adding Domains

You can host multiple mail domains on a single Mailcow server:

1. Go to Configuration → Mail Setup → Domains
2. Click Add domain and enter the new domain name
3. Configure DNS records for the new domain (MX, SPF, DKIM, DMARC) following the same pattern as in Step 2
4. Create mailboxes for the new domain

Fail2Ban – Brute-Force Protection

Your server comes with Fail2Ban pre-configured to protect SSH from brute-force attacks. Mailcow also has its own internal brute-force protection for SMTP, IMAP, POP3 and the admin panel – configure it in the admin UI under System → Configuration → Fail2ban parameters.

Useful commands:

# Check banned IPs
fail2ban-client status sshd

# Unban an IP
fail2ban-client set sshd unbanip 1.2.3.4

If you accidentally lock yourself out, open the Console on your server’s Overview tab in the client portal and unban your IP.

Service Management

# Check status
cd /opt/mailcow-dockerized && docker compose ps

# Restart all services
docker compose down && docker compose up -d

# View logs
docker compose logs -f --tail=100

Backups

Mailcow includes a built-in backup script:

# Create a backup
cd /opt/mailcow-dockerized
./helper-scripts/backup_and_restore.sh backup all --delete-days 7

# Automated daily backups (add to crontab -e)
0 3 * * * cd /opt/mailcow-dockerized && ./helper-scripts/backup_and_restore.sh backup all --delete-days 7

Backups are stored in /var/backups/mailcow by default.

Updates

To update Mailcow and system packages:

# Update Mailcow
cd /opt/mailcow-dockerized && sudo ./update.sh

# Update system packages
apt update && apt upgrade -y

Software Included

• Mailcow Documentation: docs.mailcow.email
• Mailcow DNS Setup: docs.mailcow.email/getstarted/prerequisite-dns
• Mail Tester (check deliverability): mail-tester.com