GitLab Omnibus Docker Compose with ZOHO Mail

docker-compose.yml

version: "3"
services:
  gitlab:
    image: 'gitlab/gitlab-ce:latest'
    restart: unless-stopped
    container_name: gitlab
    environment:
      GITLAB_OMNIBUS_CONFIG: |
        external_url 'http://gitlab.local'
        puma['worker_processes'] = 2
        sidekiq['concurrency'] = 2
        # Turn off monitoring to reduce idle cpu and disk usage
        prometheus_monitoring['enable'] = false
        # ZOHO Mail
        gitlab_rails['smtp_enable'] = true
        gitlab_rails['smtp_address'] = "smtp.zoho.com"
        gitlab_rails['smtp_port'] = 465
        gitlab_rails['smtp_user_name'] = "[email protected]"
        gitlab_rails['smtp_password'] = "*****"
        gitlab_rails['smtp_domain'] = "example.com"
        gitlab_rails['smtp_authentication'] = "plain"
        gitlab_rails['smtp_tls'] = true
        gitlab_rails['smtp_openssl_verify_mode'] = 'none'
        gitlab_rails['gitlab_email_enabled'] = true
        gitlab_rails['gitlab_email_from'] = '[email protected]'
        gitlab_rails['gitlab_email_display_name'] = 'Gitlab Local'
        gitlab_rails['gitlab_email_reply_to'] = '[email protected]'
    ports:
      - '80:80'
      - '443:443'
      - '222:22'
    volumes:
      - '$GITLAB_HOME/config:/etc/gitlab'
      - '$GITLAB_HOME/logs:/var/log/gitlab'
      - '$GITLAB_HOME/data:/var/opt/gitlab'
    deploy:
      resources:
          limits:
            cpus: 2
            memory: 2G
          reservations:
            cpus: 1
            memory: 1G