First login and admin setup

Open https://mail.example.com and log in with the default credentials:

• User: admin
• Password: moohoo

First three things to do — in order:

1. Change the admin password. Settings → Access → Administrators.
2. Add your domain. Email → Configuration → Domains → Add. Enable "Relay non-existing mailboxes via..." only if you bridge to another MTA.
3. Create your first mailbox. Email → Configuration → Mailboxes → Add. Pick a quota (5–10 GB is typical).

Verify HTTPS: Mailcow runs the acme-mailcow container which auto-requests a Let's Encrypt cert for MAILCOW_HOSTNAME + any autodiscover. / autoconfig. hostnames it detects. Check docker compose logs acme-mailcow if the cert isn't issued within 5 minutes.

Test sending: from the new mailbox, send to check-auth@verifier.port25.com — you'll get an authentication report back showing SPF/DKIM/DMARC alignment.