diff --git a/.env b/.env
index 9d517b8..7c6fdec 100644
--- a/.env
+++ b/.env
@@ -3,4 +3,4 @@ POSTGRES_PASS=zammad
 POSTGRES_USER=zammad
 RESTART=always
 # don't forget to add the minus before the version
-VERSION=-3.6.0-63c
+VERSION=-4.0.0-25c
\ No newline at end of file
diff --git a/.github/docker-image-build.sh b/.github/docker-image-build.sh
index f9c09e4..d119540 100755
--- a/.github/docker-image-build.sh
+++ b/.github/docker-image-build.sh
@@ -9,6 +9,6 @@ DOCKER_IMAGES="zammad zammad-elasticsearch zammad-postgresql"
 
 # shellcheck disable=SC2153
 for DOCKER_IMAGE in ${DOCKER_IMAGES}; do
-  echo "Build Zammad Docker image ${DOCKER_IMAGE} for local test"
-  docker build --pull --no-cache --build-arg BUILD_DATE="$(date -u +'%Y-%m-%dT%H:%M:%SZ')" -t "${DOCKER_IMAGE}" -f "containers/${DOCKER_IMAGE}/Dockerfile" .
+  echo "Build Zammad Docker image ${DOCKER_IMAGE} for local or ci tests"
+  docker build --pull --no-cache --build-arg BUILD_DATE="$(date -u +'%Y-%m-%dT%H:%M:%SZ')" -t "${DOCKER_IMAGE}-local" -f "containers/${DOCKER_IMAGE}/Dockerfile" .
 done
diff --git a/.github/tests.sh b/.github/tests.sh
index f143eb7..1f633f8 100755
--- a/.github/tests.sh
+++ b/.github/tests.sh
@@ -8,7 +8,7 @@ set -o pipefail
 
 docker-compose logs --timestamps --follow &
 
-until (curl -I --silent --fail localhost | grep -iq "HTTP/1.1 200 OK"); do
+until (curl -I --silent --fail localhost:8080 | grep -iq "HTTP/1.1 200 OK"); do
     echo "wait for zammad to be ready..."
     sleep 15
 done
diff --git a/.github/workflows/ci-remote-image.yaml b/.github/workflows/ci-remote-image.yaml
new file mode 100644
index 0000000..9ed0dc4
--- /dev/null
+++ b/.github/workflows/ci-remote-image.yaml
@@ -0,0 +1,26 @@
+name: ci-remote-image
+
+on:
+  pull_request:
+    paths:
+      - '.env'
+
+jobs:
+  run-remote-image-docker-compose:
+    timeout-minutes: 20
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: pull docker-compose images
+        run: docker-compose pull
+
+      - name: run docker-compose up
+        run: docker-compose up --detach
+
+      - name: add autowizard file
+        run: docker cp .github/auto_wizard.json zammad-docker-compose_zammad-railsserver_1:/opt/zammad
+
+      - name: run tests
+        run: .github/tests.sh
diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 70030b3..ff9ea53 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -10,6 +10,7 @@ jobs:
     steps:
       - name: Checkout Code
         uses: actions/checkout@v2
+
       - name: Codespell
         uses: codespell-project/actions-codespell@master
         with:
@@ -21,7 +22,8 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
+
       - name: lint zammad docker-compose file
         run: docker-compose config
 
@@ -30,6 +32,7 @@ jobs:
     steps:
       - name: Checkout Code
         uses: actions/checkout@v2
+
       - name: Lint Code Base
         uses: github/super-linter@v3
         env:
@@ -45,33 +48,16 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
+
       - name: build docker containers
         run: .github/docker-image-build.sh
-      - name: use images build by ci
-        run: sed -i -e 's#${IMAGE_REPO}:##g' -e 's#${VERSION}##g' docker-compose.yml
-      - name: run docker-compose up
-        run: docker-compose up --detach
-      - name: add autowizard file
-        run: docker cp .github/auto_wizard.json zammad-docker-compose_zammad-railsserver_1:/opt/zammad
-      - name: run tests
-        run: .github/tests.sh
 
-  run-remote-image-docker-compose:
-    needs:
-      - codespell
-      - lint-docker-compose-file
-      - super-linter
-    timeout-minutes: 10
-    runs-on: ubuntu-20.04
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v1
-      - name: pull docker-compose images
-        run: docker-compose pull
       - name: run docker-compose up
-        run: docker-compose up --detach
+        run: docker-compose -f docker-compose.yml -f docker-compose.override.yml -f docker-compose.override-local.yml up --detach
+
       - name: add autowizard file
         run: docker cp .github/auto_wizard.json zammad-docker-compose_zammad-railsserver_1:/opt/zammad
+
       - name: run tests
         run: .github/tests.sh
diff --git a/Dockerfile b/Dockerfile
index 9492c92..ea5d3d3 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -8,5 +8,5 @@ LABEL org.label-schema.build-date="$BUILD_DATE" \
       org.label-schema.vcs-url="https://github.com/colpari/zammad" \
       org.label-schema.vcs-type="Git" \
       org.label-schema.vendor="colpari" \
-      org.label-schema.schema-version="3.6.0" \
+      org.label-schema.schema-version="4.0.0" \
       org.label-schema.docker.cmd="sysctl -w vm.max_map_count=262144;docker-compose up"
diff --git a/README.md b/README.md
index d948951..2814831 100644
--- a/README.md
+++ b/README.md
@@ -70,3 +70,9 @@ CREATE USER zammad;
 ALTER USER zammad WITH PASSWORD 'zammad';
 ALTER USER zammad WITH SUPERUSER CREATEDB;
 ```
+
+### From =< 3.6.0-65
+
+To be able to run Zammad container with an unprivileged user we had to change the port Nginx uses from 80 to 8080, so Zammad needs to be accessed via <http://localhost:8080> instead of <http://localhost> now!
+
+This change will also affect you, if you use a reverse proxy, like Traefik or Haproxy, in front of Zammad as your reverse proxy configuration needs to be adapted to point to port 8080 now.
diff --git a/containers/zammad-elasticsearch/Dockerfile b/containers/zammad-elasticsearch/Dockerfile
index 5bead15..6292169 100644
--- a/containers/zammad-elasticsearch/Dockerfile
+++ b/containers/zammad-elasticsearch/Dockerfile
@@ -9,7 +9,7 @@ LABEL org.label-schema.build-date="$BUILD_DATE" \
       org.label-schema.vcs-url="https://github.com/colpari/zammad" \
       org.label-schema.vcs-type="Git" \
       org.label-schema.vendor="colpari" \
-      org.label-schema.schema-version="3.6.0" \
+      org.label-schema.schema-version="4.0.0" \
       org.label-schema.docker.cmd="sysctl -w vm.max_map_count=262144;docker-compose up"
 
 SHELL ["/bin/bash", "-e", "-o", "pipefail", "-c"]
diff --git a/containers/zammad-postgresql/Dockerfile b/containers/zammad-postgresql/Dockerfile
index 2566ae0..3e75d51 100644
--- a/containers/zammad-postgresql/Dockerfile
+++ b/containers/zammad-postgresql/Dockerfile
@@ -10,7 +10,7 @@ LABEL org.label-schema.build-date="$BUILD_DATE" \
       org.label-schema.vcs-url="https://github.com/colpari/zammad" \
       org.label-schema.vcs-type="Git" \
       org.label-schema.vendor="colpari" \
-      org.label-schema.schema-version="3.6.0" \
+      org.label-schema.schema-version="4.0.0" \
       org.label-schema.docker.cmd="sysctl -w vm.max_map_count=262144;docker-compose up"
 
 SHELL ["/bin/bash", "-e", "-o", "pipefail", "-c"]
diff --git a/containers/zammad-postgresql/backup.sh b/containers/zammad-postgresql/backup.sh
index 6774d76..6c570ee 100755
--- a/containers/zammad-postgresql/backup.sh
+++ b/containers/zammad-postgresql/backup.sh
@@ -24,7 +24,7 @@ function zammad_backup {
 
   # delete old backups
   if [ -d "${BACKUP_DIR}" ] && [ -n "$(ls "${BACKUP_DIR}")" ]; then
-    find "${BACKUP_DIR}"/*_zammad_*.gz -type f -mtime +"${HOLD_DAYS}" -exec rm {} \;
+    find "${BACKUP_DIR}"/*_zammad_*.gz -type f -mtime +"${HOLD_DAYS}" -delete
   fi
 
   if [ "${NO_FILE_BACKUP}" != "yes" ]; then
diff --git a/containers/zammad/Dockerfile b/containers/zammad/Dockerfile
index b20dde1..ec3cc48 100644
--- a/containers/zammad/Dockerfile
+++ b/containers/zammad/Dockerfile
@@ -9,6 +9,7 @@ ENV GIT_BRANCH colpari-develop
 ENV GIT_URL ${PROJECT_URL}.git
 ENV PROJECT_URL https://github.com/colpari/zammad
 ENV RAILS_ENV production
+ENV RAILS_LOG_TO_STDOUT true
 ENV TAR_GZ_URL ${PROJECT_URL}/archive/${GIT_BRANCH}.tar.gz
 ENV ZAMMAD_DIR /opt/zammad
 ENV ZAMMAD_READY_FILE ${ZAMMAD_DIR}/tmp/zammad.ready
@@ -36,11 +37,12 @@ LABEL org.label-schema.build-date="$BUILD_DATE" \
       org.label-schema.vcs-url="https://github.com/colpari/zammad" \
       org.label-schema.vcs-type="Git" \
       org.label-schema.vendor="colpari" \
-      org.label-schema.schema-version="3.6.0" \
+      org.label-schema.schema-version="4.0.0" \
       org.label-schema.docker.cmd="sysctl -w vm.max_map_count=262144;docker-compose up"
 
 ENV GIT_BRANCH colpari-develop
 ENV RAILS_ENV production
+ENV RAILS_LOG_TO_STDOUT true
 ENV ZAMMAD_DIR /opt/zammad
 ENV ZAMMAD_READY_FILE ${ZAMMAD_DIR}/tmp/zammad.ready
 ENV ZAMMAD_TMP_DIR /tmp/zammad-${GIT_BRANCH}
diff --git a/containers/zammad/docker-entrypoint.sh b/containers/zammad/docker-entrypoint.sh
index d1faf87..2c0e850 100755
--- a/containers/zammad/docker-entrypoint.sh
+++ b/containers/zammad/docker-entrypoint.sh
@@ -12,6 +12,7 @@ set -e
 : "${ELASTICSEARCH_SSL_VERIFY:=true}"
 : "${MEMCACHED_HOST:=zammad-memcached}"
 : "${MEMCACHED_PORT:=11211}"
+: "${NGINX_PORT:=8080}"
 : "${NGINX_SERVER_NAME:=_}"
 : "${NGINX_SERVER_SCHEME:=\$scheme}"
 : "${POSTGRESQL_HOST:=zammad-postgresql}"
@@ -120,7 +121,8 @@ if [ "$1" = 'zammad-nginx' ]; then
   check_zammad_ready
 
   # configure nginx
-  sed -e "s#proxy_set_header X-Forwarded-Proto .*;#proxy_set_header X-Forwarded-Proto ${NGINX_SERVER_SCHEME};#g" \
+  sed -e "s#\(listen\)\(.*\)80#\1\2${NGINX_PORT}#g" \
+      -e "s#proxy_set_header X-Forwarded-Proto .*;#proxy_set_header X-Forwarded-Proto ${NGINX_SERVER_SCHEME};#g" \
       -e "s#server .*:3000#server ${ZAMMAD_RAILSSERVER_HOST}:${ZAMMAD_RAILSSERVER_PORT}#g" \
       -e "s#server .*:6042#server ${ZAMMAD_WEBSOCKET_HOST}:${ZAMMAD_WEBSOCKET_PORT}#g" \
       -e "s#server_name .*#server_name ${NGINX_SERVER_NAME};#g" \
diff --git a/containers/zammad/setup.sh b/containers/zammad/setup.sh
index 3bbf654..47160f3 100755
--- a/containers/zammad/setup.sh
+++ b/containers/zammad/setup.sh
@@ -3,7 +3,7 @@ set -e
 
 # install dependencies
 if [ "$1" = 'builder' ]; then
-  PACKAGES="build-essential curl git libimlib2-dev libpq-dev"
+  PACKAGES="build-essential curl git libimlib2-dev libpq-dev shared-mime-info"
 elif [ "$1" = 'runner' ]; then
   PACKAGES="curl libimlib2 libpq5 nginx rsync"
 fi
@@ -28,7 +28,6 @@ if [ "$1" = 'builder' ]; then
   contrib/packager.io/fetch_locales.rb
   sed -e 's#.*adapter: postgresql#  adapter: nulldb#g' -e 's#.*username:.*#  username: postgres#g' -e 's#.*password:.*#  password: \n  host: zammad-postgresql\n#g' < contrib/packager.io/database.yml.pkgr > config/database.yml
   sed -i "/require 'rails\/all'/a require\ 'nulldb'" config/application.rb
-  sed -i '/# Use a different logger for distributed setups./a \ \ config.logger = Logger.new(STDOUT)' config/environments/production.rb
   sed -i 's/.*scheduler_\(err\|out\).log.*//g' script/scheduler.rb
   touch db/schema.rb
   bundle exec rake assets:precompile
diff --git a/docker-compose.override-local.yml b/docker-compose.override-local.yml
new file mode 100644
index 0000000..26a0ebf
--- /dev/null
+++ b/docker-compose.override-local.yml
@@ -0,0 +1,27 @@
+version: '2'
+
+services:
+
+  zammad-backup:
+    image: zammad-postgresql-local
+
+  zammad-elasticsearch:
+    image: zammad-elasticsearch-local
+
+  zammad-init:
+    image: zammad-local
+
+  zammad-nginx:
+    image: zammad-local
+
+  zammad-postgresql:
+    image: zammad-postgresql-local
+
+  zammad-railsserver:
+    image: zammad-local
+
+  zammad-scheduler:
+    image: zammad-local
+
+  zammad-websocket:
+    image: zammad-local
diff --git a/docker-compose.override.yml b/docker-compose.override.yml
index 22e5cc4..c685a51 100644
--- a/docker-compose.override.yml
+++ b/docker-compose.override.yml
@@ -3,4 +3,4 @@ services:
 
   zammad-nginx:
     ports:
-      - "80:80"
+      - "8080:8080"
diff --git a/docker-compose.yml b/docker-compose.yml
index 3b5fff6..7c3b90d 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -51,7 +51,7 @@ services:
   zammad-nginx:
     command: ["zammad-nginx"]
     expose:
-      - "80"
+      - "8080"
     depends_on:
       - zammad-railsserver
     image: ${IMAGE_REPO}:zammad${VERSION}