title: Docker pgadmin 4 - error: "does not appear to be a valid email address. Please reset the PGADMIN_DEFAULT_EMAIL environment variable"
body: <p>Please bear with me, I'm rather new to docker.</p>
  <p>I've got the following <strong>docker-compose.yaml</strong> file from my colleague who runs this on windows - apparently without problems:</p>
  <pre><code>version: &quot;3.3&quot;
  
  services:
    mysql-server:
      image: mysql:8.0.19
      restart: always
      environment:
        MYSQL_ROOT_PASSWORD: secret
      volumes:
        - mysql-data:/var/lib/mysql
      ports:
        - &quot;33061:33061&quot;
  
    phpmyadmin:
      image: phpmyadmin/phpmyadmin:5.1.1
      restart: always
      environment:
        PMA_HOST: mysql-server
        PMA_USER: ${PMA_USER}
        PMA_PASSWORD: ${PMA_PASSWORD}
        UPLOAD_LIMIT: 256M
        MAX_EXECUTION_TIME: 0
      ports:
        - &quot;8080:80&quot;
      volumes:
        - ./database/config.user.inc.php:/etc/phpmyadmin/config.user.inc.php
  
    postgresdb:
      container_name: pg_container
      image: postgres:latest
      restart: always
      ports: 
        - &quot;54321:54321&quot;
      environment:
        - POSTGRES_USER=${POSTGRES_USER}
        - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
        - POSTGRES_DB=${POSTGRES_DB}
      volumes:
        - postgres:/var/lib/postgresql/data
  
    pgadmin:
      container_name: pgadmin_container
      depends_on: 
        - postgresdb
      image: dpage/pgadmin4:5
      restart: always
      ports:
        - &quot;5556:80&quot;
      environment:
        - PGADMIN_DEFAULT_EMAIL=${PGADMIN_DEFAULT_EMAIL}
        - PGADMIN_DEFAULT_PASSWORD=${PGADMIN_DEFAULT_PASSWORD}
      volumes:
        - pgadmin:/var/lib/pgadmin
  
    web:
      build:
        context: .
        dockerfile: dockerfile-python
      command: python3 manage.py runserver 0.0.0.0:8000
      container_name: python_myApp
      volumes:
        - .:/theApp
      ports:
        - &quot;8000:8000&quot;
      depends_on:
        - postgresdb
   
  volumes:
    mysql-data:
    postgres:
    pgadmin:
  </code></pre>
  <p>I run it on Linux, version is: <strong>Docker version 20.10.9, build c2ea9bc</strong></p>
  <p>Problem is, container <strong>pgadmin</strong> won't start up - it gives me the following error:</p>
  <pre><code>'&quot;server@myapp.de&quot;' does not appear to be a valid email address. Please reset the PGADMIN_DEFAULT_EMAIL environment variable and try again.
  </code></pre>
  <p>The <strong>.env</strong> file looks like that:</p>
  <pre><code>PMA_USER=&quot;root&quot;
  PMA_PASSWORD=&quot;XXXX&quot;
  
  POSTGRES_DB='postgres'
  POSTGRES_USER='admin'
  POSTGRES_PASSWORD='XXXX'
  
  PGADMIN_DEFAULT_EMAIL=&quot;server@myapp.de&quot;
  PGADMIN_DEFAULT_PASSWORD=&quot;XXXX&quot;
  </code></pre>
  <p>I tried to reset everything by doing a</p>
  <pre><code>docker system prune  
  docker volume prune
  </code></pre>
  <p>but the error persists. What's going wrong here?</p>
  <p>thanks!</p>