anchor.diff:          User = cfg.user;
           Group = cfg.group;
           RuntimeDirectory = optional (cfg.socket == defaultSock) "opendkim";
  -        PermissionsStartOnly = true;
         };
       };
   
  
positive.code: 
      environment.systemPackages = [ pkgs.opendkim ];
  
      systemd.services.opendkim = {
        description = "OpenDKIM signing and verification daemon";
        after = [ "network.target" ];
        wantedBy = [ "multi-user.target" ];
  
        preStart = ''
          mkdir -p "${cfg.keyPath}"
          cd "${cfg.keyPath}"
          if ! test -f ${cfg.selector}.private; then
            ${pkgs.opendkim}/bin/opendkim-genkey -s ${cfg.selector} -d all-domains-generic-key
  
negative.code:           cat ${cfg.selector}.txt
            echo "-------------------------------------------------------------"
          fi
        '';
  
        serviceConfig = {
  