Configuration Reference

Configuration Reference

This page explains the most important environment variables in plain language.

Identity and public URL

• APP_NAME: name shown on the landing page
• PUBLIC_BASE_URL: public URL where the service is reachable

Domain control

• ALLOWED_DOMAINS: comma-separated list of domains the service should answer for
• RETURN_404_FOR_UNKNOWN_DOMAIN: whether unknown domains should receive a neutral 404

Mail settings returned to clients

• MAIL_DISPLAY_NAME: long display name
• MAIL_DISPLAY_SHORT_NAME: short display name
• IMAP_HOST, IMAP_PORT, IMAP_SOCKET_TYPE, IMAP_AUTHENTICATION
• SMTP_HOST, SMTP_PORT, SMTP_SOCKET_TYPE, SMTP_AUTHENTICATION
• USERNAME_FORMAT: usually email

Proxy and logging

• TRUST_PROXY_HEADERS: enables forwarded-header processing
• TRUSTED_PROXY_IPS: restricts which peers may supply forwarded headers
• ACCESS_LOG_SKIP_PATHS: removes noisy paths from the unified access log
• DISABLE_ACCESS_LOG: disables the custom access log entirely
• LOG_LEVEL: log verbosity

Request limits and headers

• MAX_REQUEST_BODY_BYTES: maximum accepted request body size
• RATE_LIMIT_ENABLED: enables per-IP rate limiting
• RATE_LIMIT_PER_MINUTE: number of allowed requests per minute per IP
• SECURITY_HEADERS_ENABLED: enables response security headers

Protocol switches

• OUTLOOK_ENABLED
• THUNDERBIRD_ENABLED
• APPLE_MOBILECONFIG_ENABLED
• POP3_ENABLED

Disable endpoints you do not want to expose.

Related file

See the full example in .env.example.