anchor.diff:        environment.OPENSMTPD_PROC_PATH = "${procEnv}/libexec/opensmtpd";
       };
   
  -    environment.systemPackages = [ (pkgs.runCommand "opensmtpd-sendmail" {} ''
  -      mkdir -p $out/bin
  -      ln -s ${opensmtpd}/sbin/smtpctl $out/bin/sendmail
  -    '') ];
  +    environment.systemPackages = mkIf cfg.addSendmailToSystemPath [ sendmail ];
     };
   }
  
positive.code:   cfg = config.services.opensmtpd;
    conf = writeText "smtpd.conf" cfg.serverConfiguration;
    args = concatStringsSep " " cfg.extraServerArgs;
  
  in {
  
  
negative.code: 
    ###### implementation
  
    config = mkIf cfg.enable {
      users.extraGroups = {
        smtpd.gid = config.ids.gids.smtpd;
        smtpq.gid = config.ids.gids.smtpq;
  