Mail

2026-03-20 22:35:42 +00:00
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--- a/mail-relay/README.md
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+# Mail Relay - SMTP de salida para stacks
+
+Stack de relay SMTP interno para centralizar el envio de correos de tus apps sin montar un servidor de correo completo.
+
+## 📋 Descripcion
+
+Este stack despliega un relay SMTP con Postfix usando `boky/postfix` para:
+- Recibir correo SMTP desde contenedores internos
+- Reenviar todo a un proveedor SMTP externo (smarthost)
+- Firmar con DKIM (autogenerado)
+- Unificar configuracion de correo para todos los stacks
+
+No incluye recepcion de correo (MX, IMAP, POP3, webmail).
+
+## 🚀 Despliegue
+
+### 1. Preparar rutas y secreto en el host
+
+```bash
+sudo mkdir -p /opt/mail-relay/{queue,opendkim,secrets}
+sudo chmod 700 /opt/mail-relay/secrets
+printf '%s' 'CAMBIA_ESTA_PASSWORD_SMTP' | sudo tee /opt/mail-relay/secrets/relayhost_password > /dev/null
+sudo chmod 600 /opt/mail-relay/secrets/relayhost_password
+```
+
+### 2. Desplegar desde Portainer
+
+1. Ve a **Stacks** -> **Add stack**
+2. Nombre: `mail-relay`
+3. Configura el repositorio Git
+4. Compose path: `mail-relay/docker-compose.yml`
+5. Carga variables desde `mail-relay/stack.env`
+6. Ajusta al menos:
+   - `MAIL_RELAY_HOSTNAME`
+   - `MAIL_RELAY_ALLOWED_SENDER_DOMAINS`
+   - `MAIL_RELAY_MASQUERADED_DOMAINS`
+   - `MAIL_RELAY_SMARTHOST`
+   - `MAIL_RELAY_SMARTHOST_USERNAME`
+7. Deploy del stack
+
+## ⚙️ Variables importantes
+
+```env
+MAIL_RELAY_SMARTHOST=[smtp.proveedor.tld]:587
+MAIL_RELAY_SMARTHOST_USERNAME=usuario-smtp
+MAIL_RELAY_SMTP_TLS_SECURITY_LEVEL=encrypt
+MAIL_RELAY_ALLOWED_SENDER_DOMAINS=tudominio.com
+MAIL_RELAY_MASQUERADED_DOMAINS=tudominio.com
+```
+
+La password SMTP no se pone en `stack.env`; se lee desde el archivo host:
+
+```text
+/opt/mail-relay/secrets/relayhost_password
+```
+
+## 🔌 Conectar otras apps
+
+En cada stack que deba enviar correo, añade la red externa:
+
+```yaml
+networks:
+  mail_internal:
+    external: true
+```
+
+Y en el servicio de la app:
+
+```yaml
+services:
+  tu-app:
+    networks:
+      - default
+      - mail_internal
+```
+
+Config SMTP en la app:
+
+```env
+SMTP_HOST=mail-relay
+SMTP_PORT=587
+SMTP_FROM=noreply@tudominio.com
+```
+
+## ✅ DNS minimo recomendado
+
+Para buena entregabilidad en Gmail/Outlook:
+- SPF
+- DKIM
+- DMARC
+
+### SPF (ejemplo)
+
+```text
+v=spf1 include:spf.tu-proveedor.tld ~all
+```
+
+### DKIM
+
+Tras el primer arranque, extrae el TXT generado:
+
+```bash
+find /opt/mail-relay/opendkim -type f -name '*.txt' -exec echo '### {}' \; -exec cat {} \;
+```
+
+Copia esos valores a tu DNS.
+
+### DMARC (inicio en monitorizacion)
+
+```text
+v=DMARC1; p=none; adkim=s; aspf=s
+```
+
+## 🧪 Prueba rapida
+
+```bash
+docker exec -i mail-relay sendmail -t <<'EOF'
+From: noreply@tudominio.com
+To: destino@example.com
+Subject: prueba mail relay
+
+Correo de prueba del stack mail-relay.
+EOF
+```
+
+## 🛠️ Troubleshooting
+
+Ver logs:
+
+```bash
+docker logs -f mail-relay
+```
+
+Errores tipicos:
+- `Relay access denied`: revisa `MAIL_RELAY_ALLOWED_SENDER_DOMAINS`
+- Auth fallida con proveedor: revisa usuario/password SMTP
+- Rechazo por DNS: valida SPF/DKIM/DMARC
--- a/mail-relay/docker-compose.yml
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+services:
+  mail-relay:
+    image: ${MAIL_RELAY_IMAGE}
+    container_name: mail-relay
+    restart: unless-stopped
+    environment:
+      TZ: ${TZ}
+      LOG_FORMAT: ${MAIL_RELAY_LOG_FORMAT}
+
+      # Hostname del relay
+      POSTFIX_myhostname: ${MAIL_RELAY_HOSTNAME}
+
+      # Solo clientes internos del stack de correo
+      POSTFIX_mynetworks: ${MAIL_RELAY_MYNETWORKS}
+
+      # Dominios permitidos para el sender
+      ALLOWED_SENDER_DOMAINS: ${MAIL_RELAY_ALLOWED_SENDER_DOMAINS}
+
+      # Reescritura de dominio para hosts internos
+      MASQUERADED_DOMAINS: ${MAIL_RELAY_MASQUERADED_DOMAINS}
+
+      # Relay SMTP externo
+      RELAYHOST: ${MAIL_RELAY_SMARTHOST}
+      RELAYHOST_USERNAME: ${MAIL_RELAY_SMARTHOST_USERNAME}
+      RELAYHOST_PASSWORD_FILE: /run/secrets/relayhost_password
+      POSTFIX_smtp_tls_security_level: ${MAIL_RELAY_SMTP_TLS_SECURITY_LEVEL}
+
+      # DKIM
+      DKIM_AUTOGENERATE: ${MAIL_RELAY_DKIM_AUTOGENERATE}
+      DKIM_SELECTOR: ${MAIL_RELAY_DKIM_SELECTOR}
+
+    volumes:
+      - ${MAIL_RELAY_QUEUE_PATH}:/var/spool/postfix:Z
+      - ${MAIL_RELAY_DKIM_KEYS_PATH}:/etc/opendkim/keys:Z
+      - ${MAIL_RELAY_PASSWORD_FILE_PATH}:/run/secrets/relayhost_password:ro,Z
+
+    networks:
+      mail_internal:
+        ipv4_address: ${MAIL_RELAY_IPV4}
+
+    # No publicar puertos al exterior para uso interno entre contenedores.
+    # Descomenta para pruebas desde el host:
+    # ports:
+    #   - "127.0.0.1:1587:587"
+
+networks:
+  mail_internal:
+    name: ${MAIL_RELAY_NETWORK_NAME}
+    driver: bridge
+    ipam:
+      config:
+        - subnet: ${MAIL_RELAY_SUBNET}
--- a/mail-relay/stack.env
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+##### General #####
+MAIL_RELAY_IMAGE=boky/postfix:v5.1.0
+TZ=Europe/Madrid
+MAIL_RELAY_LOG_FORMAT=plain
+
+##### Network #####
+MAIL_RELAY_NETWORK_NAME=mail_internal
+MAIL_RELAY_SUBNET=10.77.0.0/24
+MAIL_RELAY_IPV4=10.77.0.10
+MAIL_RELAY_MYNETWORKS=127.0.0.0/8,10.77.0.0/24
+
+##### Relay identity #####
+MAIL_RELAY_HOSTNAME=mail.example.com
+MAIL_RELAY_ALLOWED_SENDER_DOMAINS=example.com
+MAIL_RELAY_MASQUERADED_DOMAINS=example.com
+
+##### Upstream SMTP (smarthost) #####
+MAIL_RELAY_SMARTHOST=[in-v3.mailjet.com]:587
+MAIL_RELAY_SMARTHOST_USERNAME=tu-api-key-mailjet
+MAIL_RELAY_SMTP_TLS_SECURITY_LEVEL=encrypt
+
+##### DKIM #####
+MAIL_RELAY_DKIM_AUTOGENERATE=true
+MAIL_RELAY_DKIM_SELECTOR=mail
+
+##### Host paths #####
+MAIL_RELAY_QUEUE_PATH=/opt/mail-relay/queue
+MAIL_RELAY_DKIM_KEYS_PATH=/opt/mail-relay/opendkim
+MAIL_RELAY_PASSWORD_FILE_PATH=/opt/mail-relay/secrets/relayhost_password