diff --git a/set-policyd-spf-config-for-listserver.sh b/set-policyd-spf-config-for-listserver.sh
new file mode 100755
index 0000000..1fe587c
--- /dev/null
+++ b/set-policyd-spf-config-for-listserver.sh
@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+CONF="/etc/postfix-policyd-spf-python/policyd-spf.conf"
+BACKUP="${CONF}.$(date +%Y%m%d-%H%M%S).bak"
+
+if [[ ! -f "$CONF" ]]; then
+  echo "ERROR: Config not found: $CONF" >&2
+  exit 1
+fi
+
+cp -a -- "$CONF" "$BACKUP"
+
+ensure_kv() {
+  local key="$1"
+  local value="$2"
+
+  # Prüfen ob es eine AKTIVE (nicht auskommentierte) Zeile gibt
+  if grep -Eq "^[[:space:]]*${key}[[:space:]]*=" "$CONF"; then
+    # Nur erste aktive Zeile ersetzen
+    sed -ri "0,/^[[:space:]]*${key}[[:space:]]*=.*/s//${key} = ${value}/" "$CONF"
+  else
+    # Anfügen mit Leerzeile + Kommentar
+    cat >>"$CONF" <<EOF
+
+# --- Mailinglist-friendly SPF policy (added by script) ---
+${key} = ${value}
+EOF
+  fi
+}
+
+ensure_kv "HELO_reject" "False"
+ensure_kv "Mail_From_reject" "False"
+ensure_kv "PermError_reject" "False"
+ensure_kv "TempError_Defer" "True"
+
+echo "Updated: $CONF"
+echo "Backup : $BACKUP"
+
+exit