diff --git a/.github/actions/build-postfix-exporter/action.yaml b/.github/actions/build-postfix-exporter/action.yaml
index 5b246f5..80513c7 100644
--- a/.github/actions/build-postfix-exporter/action.yaml
+++ b/.github/actions/build-postfix-exporter/action.yaml
@@ -9,6 +9,10 @@ inputs:
     description: 'Docker image tags'
     required: true
 
+env:
+  DOCKERHUB_REPO: boky/postfix-exporter
+  #GHCR_REPO: ghcr.io/bokysan/postfix-exporter
+
 runs:
   using: "composite"
   steps:
@@ -33,6 +37,22 @@ runs:
       with:
         DOCKER_ACCESS_TOKEN: '${{ inputs.DOCKER_ACCESS_TOKEN }}'
 
+    # GitHub container registry login
+    #- name: Login to GHCR
+    #  uses: docker/login-action@v3
+    #  with:
+    #    registry: ghcr.io
+    #    username: ${{ github.repository_owner }}
+    #    password: ${{ secrets.GITHUB_TOKEN }}
+
+    - name: Docker meta
+      id: meta
+      uses: docker/metadata-action@v5
+      with:
+        images: |
+          ${{ env.DOCKERHUB_REPO }}
+#          ${{ env.GHCR_REPO }}
+
     - name: Cache Docker layers
       uses: actions/cache@v4
       with:
@@ -42,11 +62,12 @@ runs:
           ${{ runner.os }}-postfix-exporter-
 
     - name: Build and push
-      uses: docker/build-push-action@v5
+      uses: docker/build-push-action@v6
       with:
         context: postfix_exporter
         push: true
         tags: '${{ inputs.tags }}'
+        labels: ${{ steps.meta.outputs.labels }}
         platforms: "linux/amd64,linux/arm/v5,linux/arm/v7,linux/arm64/v8,linux/mips64le,linux/ppc64le,linux/s390x"
         # linux/386,linux/arm/v6,linux/arm64,linux/riscv64"
         cache-from: type=local,src=/tmp/.buildx-cache/postfix-exporter,mode=max,compression=estargz
diff --git a/.github/actions/buildx-setup/action.yaml b/.github/actions/buildx-setup/action.yaml
index 11b8c90..62a9968 100644
--- a/.github/actions/buildx-setup/action.yaml
+++ b/.github/actions/buildx-setup/action.yaml
@@ -9,7 +9,7 @@ runs:
 
     - name: Set up Docker Buildx
       id: buildx
-      uses: docker/setup-buildx-action@master
+      uses: docker/setup-buildx-action@v3
       with:
         install: true
 
diff --git a/.github/workflows/tags.yml b/.github/workflows/tags.yml
index aa71cb4..a500763 100644
--- a/.github/workflows/tags.yml
+++ b/.github/workflows/tags.yml
@@ -51,8 +51,6 @@ jobs:
           tags: |
             boky/postfix-exporter:latest
             boky/postfix-exporter:edge
-          # boky/postfix-exporter:${{ env.RELEASE_VERSION }}
-          # boky/postfix-exporter:${{ env.RELEASE_VERSION_NO_v }}
 
   Build_Alpine:
     runs-on: ubuntu-latest
diff --git a/README.md b/README.md
index d2f081c..dce43a8 100644
--- a/README.md
+++ b/README.md
@@ -131,7 +131,7 @@ Several potentially "surprising" changes went into this issue and hence warrant
 - **[`master`](https://github.com/bokysan/docker-postfix/tree/master/) branch now builds images called [`edge`](https://hub.docker.com/r/boky/postfix/tags?page=1&name=edge)**. 
   `latest` images are built from the last tag. We've had several issues with people using the `latest` tag
   and reporting problems. You can now rely on `latest` being the latest stable release.
-- Image now builds its own version of [postfix-exporter](https://github.com/kumina/postfix_exporter) and relies on this
+- Image now builds its own version of [postfix-exporter](https://github.com/hsn723/postfix_exporter) and relies on this
   third-party project. Checkout is from master branch, based
   on specific SHA commit id. The same hash is used for master and tags.
 - **Architecture galore!** With the addition of debian images, we now support support more architectures than ever. The list includes: 
diff --git a/scripts/healthcheck.sh b/scripts/healthcheck.sh
index f967342..1b3ec42 100644
--- a/scripts/healthcheck.sh
+++ b/scripts/healthcheck.sh
@@ -5,7 +5,20 @@ if [ -f /tmp/container_is_terminating ]; then
 fi
 
 check_postfix() {
-    printf "EHLO healthcheck\nquit\n" | \
+    local proxy_protocol="$(postconf postscreen_upstream_proxy_protocol | cut -f2- -d= | tr -d '[:blank:]')"
+
+    check_string="EHLO healthcheck\nquit\n"
+
+    if [ -n "$proxy_protocol" ]; then
+        check_string="PROXY TCP4 127.0.0.1 127.0.0.1 587 587\n${check_string}"
+        #                   ^--- proxied internet protocol and family
+        #                        ^--- source address
+        #                                  ^--- destination address
+        #                                            ^--- source port
+        #                                                ^--- destination port
+    fi
+
+    printf "${check_string}" | \
     { while read l ; do sleep 1; echo $l; done } | \
     nc -w 2 127.0.0.1 587 | \
     grep -qE "^220.*ESMTP Postfix"