It seems that the SMTP parameters inside the docker-compose.yml
are not complete.
Please add the following and then it should work.
version: "3"
services:
grafana:
image: grafana/grafana-oss:8.2.6
container_name: grafana
volumes:
- /opt/grafana-plain/docker_volumes/grafana:/var/lib/grafana
ports:
- "3000:3000"
environment:
- 'GF_ALERTING_ENABLED=false' #disable dashboard alerting
- 'GF_UNIFIED_ALERTING_ENABLED=true' #enable alerting independent from dashboards
- 'GF_SMTP_ENABLED=true' #required to work
- 'GF_SMTP_HOST=smtp-relay.gmail.com:25' #need a valid SMTP-server:port
- 'GF_SMTP_USER=user@gmail.com' #valid user mail address
- 'GF_SMTP_PASSWORD=mysamplePassword' #valid user password
Also, you may not need to install an SMTP server for this as it should work OR best if you have already one as your company OR home lab server then use it for SMTP.