diff --git a/scripts/update.sh b/scripts/update.sh
index 116307e..b8e714b 100644
--- a/scripts/update.sh
+++ b/scripts/update.sh
@@ -341,19 +341,21 @@ JAILEOF
     fi
   fi
 
-  # Postfix: Hostname in mydestination eintragen damit System-Mails (cron, PHP)
-  # nicht als Relay-Versuch gewertet werden und fail2ban die eigene IP nicht bannt
-  if command -v postconf >/dev/null 2>&1; then
-    local srv_host
-    srv_host=$(hostname -f 2>/dev/null || hostname 2>/dev/null || true)
-    if [[ -n "$srv_host" ]]; then
-      local current_dest
-      current_dest=$(postconf -h mydestination 2>/dev/null || true)
-      if ! echo "$current_dest" | grep -qF "$srv_host"; then
-        postconf -e "mydestination = $srv_host, localhost.localdomain, localhost"
-        postfix reload >/dev/null 2>&1 || true
-        echo "[✓] Postfix: $srv_host zu mydestination hinzugefügt (System-Mails lokal zugestellt)."
-      fi
+  # Postfix: myhostname + $myhostname in mydestination eintragen damit System-Mails
+  # (cron, PHP mail()) nicht als Relay-Versuch gewertet werden
+  local POSTCONF=/usr/sbin/postconf
+  local POSTFIX=/usr/sbin/postfix
+  if [[ -x "$POSTCONF" ]]; then
+    local pf_host
+    pf_host=$("$POSTCONF" -h myhostname 2>/dev/null || true)
+    local current_dest
+    current_dest=$("$POSTCONF" -h mydestination 2>/dev/null || true)
+    local need_update=0
+    [[ -n "$pf_host" ]] && ! echo "$current_dest" | grep -qF "$pf_host" && need_update=1
+    if [[ "$need_update" -eq 1 ]]; then
+      "$POSTCONF" -e "mydestination = $pf_host, \$myhostname, localhost.localdomain, localhost"
+      [[ -x "$POSTFIX" ]] && "$POSTFIX" reload >/dev/null 2>&1 || true
+      echo "[✓] Postfix: $pf_host zu mydestination hinzugefügt (System-Mails lokal zugestellt)."
     fi
   fi
 }