fix issue with headers order -correct DKIM now.

pymta-server.service

@@ -0,0 +1,32 @@
+[Unit]
+Description=PyMTA Email Server
+After=network.target
+StartLimitIntervalSec=0
+# check any errors when using this service:
+# journalctl -u pymta-server.service -b -f
+
+[Service]
+Type=simple
+User=appuser
+Group=appuser
+WorkingDirectory=/opt/PyMTA-server
+Environment=PYTHONUNBUFFERED=1
+ExecStart=/opt/PyMTA-server/.venv/bin/python main.py
+Restart=always
+RestartSec=5
+StandardOutput=journal
+StandardError=journal
+
+# Security settings
+# Capabilities for low ports < 1024 following 2 lines:
+AmbientCapabilities=CAP_NET_BIND_SERVICE
+CapabilityBoundingSet=CAP_NET_BIND_SERVICE
+# if using port < 1024 comment out line bellow:
+# NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ReadWritePaths=/opt/PyMTA-server
+ProtectHome=true
+
+[Install]
+WantedBy=multi-user.target