anchor.diff:          type = types.bool;
           default = false;
           description = "Whether to enable the OpenSMTPD server.";
  +      };
  +
  +      addSendmailToSystemPath = mkOption {
  +        type = types.bool;
  +        default = true;
  +        description = ''
  +          Whether to add OpenSMTPD's sendmail binary to the
  +          system path or not.
  +        '';
         };
   
         extraServerArgs = mkOption {
  
positive.code:   cfg = config.services.opensmtpd;
    conf = writeText "smtpd.conf" cfg.serverConfiguration;
    args = concatStringsSep " " cfg.extraServerArgs;
  
  in {
  
  
negative.code:       environment.OPENSMTPD_PROC_PATH = "${procEnv}/libexec/opensmtpd";
      };
  
      environment.systemPackages = mkIf cfg.addSendmailToSystemPath [ sendmail ];
    };
  }
  