diff -ruN netqmail-1.06-original/chkuser.c netqmail-1.06/chkuser.c
--- netqmail-1.06-original/chkuser.c	2022-12-17 13:03:41.063181896 +0100
+++ netqmail-1.06/chkuser.c	2023-03-27 14:46:53.539833646 +0200
@@ -435,9 +435,11 @@
 	if (strncmp (domain->s, "xn--", 4) == 0) {
 		if (strstr (&domain->s[4], "--") != NULL)
 			return 0;
+/* allowing domains with hyphens like y--s.co.jp
 	} else {
 		if (strstr (domain->s, "--") != NULL)
 			return 0;
+*/
 	}
         if (strstr (domain->s, ".-") != NULL) {
                 return 0;
diff -ruN netqmail-1.06-original/chkuser_settings.h netqmail-1.06/chkuser_settings.h
--- netqmail-1.06-original/chkuser_settings.h	2022-12-17 14:31:05.145354477 +0100
+++ netqmail-1.06/chkuser_settings.h	2023-03-27 15:05:21.822633702 +0200
@@ -114,7 +114,7 @@
  * Defining it as "RELAYCLIENT" will avoid sender checking for authenticated/authorized users.
  *	Senders will be logged anyway if CHKUSER_LOG_VALID_SENDER is defined.
  */
-#define CHKUSER_SENDER_NOCHECK_VARIABLE "RELAYCLIENT"
+/* #define CHKUSER_SENDER_NOCHECK_VARIABLE "RELAYCLIENT" */
 
 /*
  * Uncomment to enable usage of "#" and "+" characters within sender address
diff -ruN netqmail-1.06-original/qmail-smtpd.c netqmail-1.06/qmail-smtpd.c
--- netqmail-1.06-original/qmail-smtpd.c	2023-03-18 17:07:30.643116714 +0100
+++ netqmail-1.06/qmail-smtpd.c	2023-03-26 20:12:34.801870237 +0200
@@ -116,10 +116,10 @@
 void out(s) char *s; { substdio_puts(&ssout,s); }
 
 void die_read(char *reason) { logit2("read failed", reason); flush(); _exit(1); }
-void die_alarm() { qlogenvelope("rejected","alarmtimeout","","451"); logit("timeout"); out("451 timeout (#4.4.2)\r\n"); flush(); _exit(1); }
-void die_nomem() { qlogenvelope("rejected","outofmemory","","421"); out("421 out of memory (#4.3.0)\r\n"); flush(); _exit(1); }
-void die_control() { qlogenvelope("rejected","cannotreadcontrols","","421"); logit("unable to read controls"); out("421 unable to read controls (#4.3.0)\r\n"); flush(); _exit(1); }
-void die_ipme() { qlogenvelope("rejected","unknownipme","","553"); logit("unable to figure out my IP addresses"); out("421 unable to figure out my IP addresses (#4.3.0)\r\n"); flush(); _exit(1); }
+void die_alarm() { qlogenvelope("rejected","alarmtimeout","","451"); out("451 timeout (#4.4.2)\r\n"); flush(); _exit(1); }
+void die_nomem() { qlogenvelope("rejected","out_of_memory","","421"); out("421 out of memory (#4.3.0)\r\n"); flush(); _exit(1); }
+void die_control() { qlogenvelope("rejected","cannot_read_controls","","421"); out("421 unable to read controls (#4.3.0)\r\n"); flush(); _exit(1); }
+void die_ipme() { qlogenvelope("rejected","unknown_ip_me","","553"); out("421 unable to figure out my IP addresses (#4.3.0)\r\n"); flush(); _exit(1); }
 /* rbl: start */
 /*
 void die_dnsbl(arg)
@@ -135,20 +135,19 @@
 void err_maxrcpt()
 {
   out("553 max rcpt limit exceeded (#5.7.1)\r\n");
-  logit("max rcpt limit exceeded (qmail-maxrcpt)");
-  qlogenvelope("rejected","maxrcpt","","553");
+  qlogenvelope("rejected","max_rcpt_exceeded","","553");
   flush();
 }
-void straynewline() { qlogenvelope("rejected","badnewlines","","451"); logit("bad newlines"); out("451 See http://pobox.com/~djb/docs/smtplf.html.\r\n"); flush(); _exit(1); }
+void straynewline() { qlogenvelope("rejected","bad_newlines","","451"); out("451 See http://pobox.com/~djb/docs/smtplf.html.\r\n"); flush(); _exit(1); }
 void die_pre_greet() { qlogenvelope("rejected","pregreet","","554"); out("554 SMTP protocol violation\r\n"); flush(); _exit(1); }
 
-void err_size() { qlogreceived("rejected","size","","552"); out("552 sorry, that message size exceeds my databytes limit (#5.3.4)\r\n"); }
+void err_size() { qlogreceived("rejected","databytes_limit_exceeded","","552"); out("552 sorry, that message size exceeds my databytes limit (#5.3.4)\r\n"); }
 #ifndef TLS
-void err_nogateway() { qlogenvelope("rejected","notinrcpthosts","","553"); out("553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)\r\n"); }
+void err_nogateway() { qlogenvelope("rejected","not_in_rcpthosts","","553"); out("553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)\r\n"); }
 #else
 void err_nogateway()
 {
-  qlogenvelope("rejected","notinrcpthosts","","553"); out("553 sorry, that domain isn't in my list of allowed rcpthosts");
+  qlogenvelope("rejected","not_in_rcpthosts","","553"); out("553 sorry, that domain isn't in my list of allowed rcpthosts");
   tls_nogateway();
   out(" (#5.7.1)\r\n");
 }
@@ -1864,11 +1863,10 @@
   qmail_put(&qqt,rcptto.s,rcptto.len);
  
   qqx = qmail_close(&qqt);
-  if (!*qqx) { acceptmessage(qp); logit("message accepted"); qlogreceived("accepted","queueaccept","","250"); return; }
+  if (!*qqx) { acceptmessage(qp); qlogreceived("accepted","queueaccept","","250"); return; }
   if (hops) {
     out("554 too many hops, this message is looping (#5.4.6)\r\n");
-    logit("message looping");
-    qlogreceived("rejected","mailloop","","554");
+    qlogreceived("rejected","message_loop","","554");
     return;
   }
   if (databytes) if (!bytestooverflow) {
@@ -1879,11 +1877,9 @@
   if (*qqx == 'D') {
     out("554 ");
     qlogreceived("rejected","queuereject",qqx + 1,"554");
-    logit2("message rejected", qqx + 1);
   } else {
     out("451 ");
-    qlogreceived("rejected","queuedelay",qqx + 1,"451");
-    logit2("message delayed", qqx + 1);
+    qlogreceived("rejected","queue_delay",qqx + 1,"451");
   }
   out(qqx + 1);
   out("\r\n");