MailSend/.env.example

APP_PORT=3025
APP_BASE_URL=https://mailhub.example.com
ADMIN_USER=admin
ADMIN_EMAIL=admin@example.com
ADMIN_PASSWORD=change-this-admin-password
SESSION_SECRET=change-this-long-random-session-secret
# Require administrator approval after a newly registered user verifies their email.
REGISTRATION_REQUIRES_APPROVAL=false

# Legacy admin send token. New users should generate their own token in the web UI.
API_TOKEN=change-this-legacy-api-token
SUBMISSION_ENABLED=true
SUBMISSION_HOST=smtp.mailhub.example.com
SUBMISSION_BIND=0.0.0.0
SUBMISSION_PORTS=25:smtp,587:smtp,465:smtps,2525:smtp
SUBMISSION_ALT_PORT=2525
SUBMISSION_ALLOW_INSECURE_AUTH=false
SUBMISSION_TLS_CERT=/certs/mailhub.example.com.crt
SUBMISSION_TLS_KEY=/certs/mailhub.example.com.key
# Optional host directory containing fullchain.pem and privkey.pem. Deploy and scheduled jobs sync it into ./certs.
# The sync detects the running app container group, writes cert=0644/key=0640, and verifies container ports 465 and 993.
MAILHUB_CERT_SOURCE_DIR=
SUBMISSION_USERNAME=change-this-smtp-user
SUBMISSION_PASSWORD=change-this-smtp-password

# Legacy Node protocol backend only. Docker Compose always exposes Dovecot on
# 143/993 and 110/995; use IMAP_BIND/POP3_BIND or a Compose override/firewall
# when either public protocol must be restricted.
IMAP_ENABLED=true
IMAP_BIND=0.0.0.0
IMAP_PORTS=143:imap,993:imaps
POP3_ENABLED=true
POP3_BIND=0.0.0.0
POP3_PORTS=110:pop3,995:pop3s
MAIL_ACCESS_ALLOW_INSECURE_AUTH=false

# Docker deployments delegate IMAP/POP3 to Dovecot. The authentication bridge
# is available only on the private Compose network and uses a generated secret.
MAIL_ACCESS_BACKEND=dovecot
DOVECOT_AUTH_ENABLED=true
DOVECOT_AUTH_HOST=0.0.0.0
DOVECOT_AUTH_PORT=3001
DOVECOT_AUTH_SECRET_FILE=/run/secrets/dovecot_auth_secret
# Low-resource hosts should keep CPU-bound password verification concurrency modest.
UV_THREADPOOL_SIZE=2
# Relative path for host-side migration commands. Compose overrides this with /data/maildir.
MAILDIR_ROOT=./data/maildir
MAILDIR_SYNC_INTERVAL_MS=300000

# Optional Roundcube one-click login. The browser receives only a single-use
# POST ticket; Roundcube exchanges it over the private network for an expiring
# mhw_ credential. Generate a separate hexadecimal secret at
# ./data/secrets/webmail_sso_secret and expose it read-only to Roundcube.
WEBMAIL_SSO_URL=
WEBMAIL_SSO_SECRET_FILE=./data/secrets/webmail_sso_secret
# Host-side reader gid for a same-host Roundcube PHP worker. Debian/Apache
# images commonly use www-data gid 33. Leave 1000 when no external reader exists.
WEBMAIL_SSO_READER_GID=1000
WEBMAIL_SSO_TICKET_TTL_SECONDS=60
WEBMAIL_SSO_CREDENTIAL_TTL_SECONDS=43200

# Outbound hostname is authorized through the SPF a: mechanism and used for HELO/Postfix.
# The sending IP drives the managed A record and PTR health check, not a direct SPF ip4 entry.
MAIL_HOSTNAME=smtp.mailhub.example.com
SENDING_IP=203.0.113.10

# Extra SPF mechanisms to preserve coexistence with third-party senders.
# Examples: include:spf.mailjet.com include:_netblocks.m.feishu.cn
DEFAULT_SPF_MECHANISMS=
DNS_RESOLVERS=1.1.1.1,8.8.8.8
DNS_AUTO_CHECK_ENABLED=true
DNS_AUTO_CHECK_INTERVAL_MS=60000
DNS_AUTO_CHECK_LIMIT=25

# SMTP service used by the web API. In docker-compose this is the internal Postfix service.
SMTP_HOST=postfix
SMTP_PORT=25
SMTP_HELO=smtp.mailhub.example.com
SEND_REQUIRES_VERIFIED=false
DELIVERY_TRACKING_ENABLED=true
POSTFIX_LOG_POLL_INTERVAL_MS=5000

# Engagement tracking uses opaque public links and a stable encryption key.
TRACKING_SECRET=change-this-separate-long-random-tracking-secret
ENGAGEMENT_TRACKING_ENABLED=false
TRACKING_RETENTION_DAYS=180
TRUST_PROXY=true

# Optional deliverability headers. One-click should only be enabled when the URL accepts compliant unsubscribe POSTs.
LIST_UNSUBSCRIBE_MAILTO=
LIST_UNSUBSCRIBE_URL=
LIST_UNSUBSCRIBE_POST_ENABLED=false
FEEDBACK_ID_ENABLED=true
REPORT_ABUSE_TO=
CSA_COMPLAINTS_TO=

# Optional bounce envelope sender. Keep disabled until this mailbox/domain receives and processes bounces.
BOUNCE_ADDRESS=
BOUNCE_ENVELOPE_ENABLED=false

# DMARC defaults.
DMARC_POLICY=none
DMARC_RUA=