anchor.diff:          spool_directory = ${cfg.spoolDir}
           ${cfg.config}
         '';
  -      systemPackages = [ exim ];
  +      systemPackages = [ cfg.package ];
       };
   
       users.users = singleton {
  
positive.code:         '';
        };
  
      };
  
    };
  
negative.code:       gid = config.ids.gids.exim;
      };
  
      security.wrappers.exim.source = "${cfg.package}/bin/exim";
  
      systemd.services.exim = {
        description = "Exim Mail Daemon";
        wantedBy = [ "multi-user.target" ];
        restartTriggers = [ config.environment.etc."exim.conf".source ];
        serviceConfig = {
          ExecStart   = "${cfg.package}/bin/exim -bdf -q30m";
          ExecReload  = "${coreutils}/bin/kill -HUP $MAINPID";
        };
        preStart = ''
  