self-hosted mailtrain error: nc: getaddrinfo: Name does not resolve

[shadowaero]

Trying to install mailtrain for docker. I get this error in log of mailtrain nc: getaddrinfo: Name does not resolve.
All 3 containers are tied to the network mailtrain_net.

Here is log from mariadb
2025-10-17 16:13:56 0 [Note] InnoDB: File './ibtmp1' size is now 12 MB.
2025-10-17 16:13:56 0 [Note] InnoDB: 10.6.23 started; log sequence number 42790; transaction id 14
2025-10-17 16:13:56 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2025-10-17 16:13:56 0 [Note] Plugin 'FEEDBACK' is disabled.
2025-10-17 16:13:56 0 [Note] InnoDB: Buffer pool(s) load completed at 251017 16:13:56
2025-10-17 16:13:56 0 [Warning] You need to use --log-bin to make --expire-logs-days or --binlog-expire-logs-seconds work.
2025-10-17 16:13:56 0 [Note] Server socket created on IP: '0.0.0.0'.
2025-10-17 16:13:56 0 [Note] Server socket created on IP: '::'.
2025-10-17 16:13:56 0 [Note] mariadbd: ready for connections.
Version: '10.6.23-MariaDB-ubu2204' socket: '/run/mysqld/mysqld.sock' port: 3306 mariadb.org binary distribution
2025-10-17 16:14:05 3 [Warning] Access denied for user 'root'@'localhost' (using password: NO)

Redis says waiting for connection.

Here is the docker compose (portainer stack). Passwords and usernames are not real. I have tried both external and internal networks.
services:
mailtrain:
image: mailtrain/mailtrain:latest
container_name: mailtrain
restart: always
ports:
- 8090:3000
environment:
- PUID=999
- PGID=10
- TZ=America/New_York
# --- Database ---
- DB_HOST=mariadb
- DB_USER=mailtrain
- DB_PASS=ABC123
- DB_NAME=mailtrain
- REDIS_HOST=redis
# --- SMTP (Gmail) ---
- SMTP_HOST=smtp.gmail.com
- SMTP_PORT=587
- SMTP_USERNAME=ABC123@gmail.com
- SMTP_PASSWORD=abcdabcdabcd
- SMTP_SECURE=true # If auth fails on 587, set to "false" for STARTTLS
- MAIL_FROM_ADDRESS=mailtrain@abc.com
depends_on:
- mariadb
- redis
volumes:
- /volume1/docker/mailtrain/config:/config
- /volume1/docker/mailtrain/data:/data
networks:
- mailtrain_net
command: sh -c "sleep 10 && node index.js"

mariadb:
image: mariadb:10.6
container_name: mariadb2
restart: always
environment:
- MYSQL_ROOT_PASSWORD=ABC123
- MYSQL_DATABASE=mailtrain
- MYSQL_USER=mailtrain
- MYSQL_PASSWORD=ABC123
- TZ=America/New_York
volumes:
- /volume1/docker/mariadb2/data:/var/lib/mysql
healthcheck:
test: ["CMD", "mysqladmin", "ping", "-h", "localhost"]
interval: 10s
timeout: 5s
retries: 5
networks:
- mailtrain_net

redis:
image: redis:6
container_name: redis
restart: always
command: ["redis-server", "--appendonly", "yes"]
volumes:
- /volume1/docker/redis/data:/data
healthcheck:
test: ["CMD", "redis-cli", "PING"]
interval: 10s
timeout: 5s
retries: 5
networks:
- mailtrain_net

networks:
mailtrain_net:
external: true

I can follow instructions but do not know the linux commands to do alot of stuff. I followed Chatgpt5 and gemini 2.5pro to do a lot of troubleshooting but nothing worked.

thank you in advance for any help or comments.