diff --git a/src/global/mail_params.c b/src/global/mail_params.c
index 91c70f7..483613c 100644
--- a/src/global/mail_params.c
+++ b/src/global/mail_params.c
@@ -379,6 +379,8 @@ int     warn_compat_break_smtputf8_enable;
 int     warn_compat_break_chroot;
 int     warn_compat_break_relay_restrictions;
 
+bool    var_rhel_ipv6_normalize;
+
 /* check_myhostname - lookup hostname and validate */
 
 static const char *check_myhostname(void)
@@ -825,6 +827,7 @@ void    mail_params_init()
 	VAR_LONG_QUEUE_IDS, DEF_LONG_QUEUE_IDS, &var_long_queue_ids,
 	VAR_STRICT_SMTPUTF8, DEF_STRICT_SMTPUTF8, &var_strict_smtputf8,
 	VAR_ENABLE_ORCPT, DEF_ENABLE_ORCPT, &var_enable_orcpt,
+	VAR_RHEL_IPV6_NORMALIZE, DEF_RHEL_IPV6_NORMALIZE, &var_rhel_ipv6_normalize,
 	0,
     };
     const char *cp;
diff --git a/src/global/mail_params.h b/src/global/mail_params.h
index e4358ca..74459d9 100644
--- a/src/global/mail_params.h
+++ b/src/global/mail_params.h
@@ -3153,7 +3153,7 @@ extern char *var_local_rwr_clients;
   * EHLO keyword filter.
   */
 #define VAR_SMTPD_EHLO_DIS_WORDS	"smtpd_discard_ehlo_keywords"
-#define DEF_SMTPD_EHLO_DIS_WORDS	""
+#define DEF_SMTPD_EHLO_DIS_WORDS	"chunking"
 extern char *var_smtpd_ehlo_dis_words;
 
 #define VAR_SMTPD_EHLO_DIS_MAPS		"smtpd_discard_ehlo_keyword_address_maps"
@@ -4199,9 +4199,13 @@ extern int var_postlogd_watchdog;
 #define INFO_LOG_ADDR_FORM_NAME_INTERNAL	"internal"
 
 #define VAR_INFO_LOG_ADDR_FORM	"info_log_address_format"
-#define DEF_INFO_LOG_ADDR_FORM	INFO_LOG_ADDR_FORM_NAME_EXTERNAL
+#define DEF_INFO_LOG_ADDR_FORM	INFO_LOG_ADDR_FORM_NAME_INTERNAL
 extern char *var_info_log_addr_form;
 
+#define VAR_RHEL_IPV6_NORMALIZE	"rhel_ipv6_normalize"
+#define DEF_RHEL_IPV6_NORMALIZE	0
+extern bool var_rhel_ipv6_normalize;
+
 /* LICENSE
 /* .ad
 /* .fi
diff --git a/src/smtpd/smtpd.c b/src/smtpd/smtpd.c
index da7227f..53e640e 100644
--- a/src/smtpd/smtpd.c
+++ b/src/smtpd/smtpd.c
@@ -4334,6 +4334,7 @@ static int xclient_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
     SMTPD_TOKEN *argp;
     char   *raw_value;
     char   *attr_value;
+    const char *bare_value;
     char   *attr_name;
     int     update_namaddr = 0;
     int     name_status;
@@ -4481,15 +4482,31 @@ static int xclient_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
 		UPDATE_STR(state->addr, attr_value);
 		UPDATE_STR(state->rfc_addr, attr_value);
 	    } else {
-		neuter(attr_value, NEUTER_CHARACTERS, '?');
-		if (normalize_mailhost_addr(attr_value, &state->rfc_addr,
+		if (var_rhel_ipv6_normalize) {
+			neuter(attr_value, NEUTER_CHARACTERS, '?');
+		}
+		if ((var_rhel_ipv6_normalize &&
+		    normalize_mailhost_addr(attr_value, &state->rfc_addr,
 					    &state->addr,
-					    &state->addr_family) < 0) {
+					    &state->addr_family) < 0) ||
+		    (!var_rhel_ipv6_normalize &&
+			(bare_value = valid_mailhost_addr(attr_value, DONT_GRIPE)) == 0)) {
 		    state->error_mask |= MAIL_ERROR_PROTOCOL;
 		    smtpd_chat_reply(state, "501 5.5.4 Bad %s syntax: %s",
 				     XCLIENT_ADDR, attr_value);
 		    return (-1);
 		}
+		if (!var_rhel_ipv6_normalize) {
+		    UPDATE_STR(state->addr, bare_value);
+		    UPDATE_STR(state->rfc_addr, attr_value);
+#ifdef HAS_IPV6
+		    if (strncasecmp(attr_value, INET_PROTO_NAME_IPV6 ":",
+			    sizeof(INET_PROTO_NAME_IPV6 ":") - 1) == 0)
+			state->addr_family = AF_INET6;
+		    else
+#endif
+			state->addr_family = AF_INET;
+                }
 	    }
 	    update_namaddr = 1;
 	}
@@ -4569,17 +4586,25 @@ static int xclient_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
 		attr_value = SERVER_ADDR_UNKNOWN;
 		UPDATE_STR(state->dest_addr, attr_value);
 	    } else {
+		if (var_rhel_ipv6_normalize) {
 #define NO_NORM_RFC_ADDR		((char **) 0)
 #define NO_NORM_ADDR_FAMILY	((int *) 0)
-		neuter(attr_value, NEUTER_CHARACTERS, '?');
-		if (normalize_mailhost_addr(attr_value, NO_NORM_RFC_ADDR,
+			neuter(attr_value, NEUTER_CHARACTERS, '?');
+		}
+		if ((var_rhel_ipv6_normalize &&
+		    normalize_mailhost_addr(attr_value, NO_NORM_RFC_ADDR,
 					    &state->dest_addr,
-					    NO_NORM_ADDR_FAMILY) < 0) {
+					    NO_NORM_ADDR_FAMILY) < 0) ||
+		    (!var_rhel_ipv6_normalize &&
+			(bare_value = valid_mailhost_addr(attr_value, DONT_GRIPE)) == 0)) {
 		    state->error_mask |= MAIL_ERROR_PROTOCOL;
 		    smtpd_chat_reply(state, "501 5.5.4 Bad %s syntax: %s",
 				     XCLIENT_DESTADDR, attr_value);
 		    return (-1);
 		}
+		if (!var_rhel_ipv6_normalize) {
+			UPDATE_STR(state->dest_addr, bare_value);
+		}
 	    }
 	    /* XXX Require same address family as client address. */
 	}
@@ -4690,6 +4715,7 @@ static int xforward_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
     SMTPD_TOKEN *argp;
     char   *raw_value;
     char   *attr_value;
+    const char *bare_value;
     char   *attr_name;
     int     updated = 0;
     static const NAME_CODE xforward_flags[] = {
@@ -4808,15 +4834,22 @@ static int xforward_cmd(SMTPD_STATE *state, int argc, SMTPD_TOKEN *argv)
 		UPDATE_STR(state->xforward.addr, attr_value);
 	    } else {
 		neuter(attr_value, NEUTER_CHARACTERS, '?');
-		if (normalize_mailhost_addr(attr_value,
+		if ((var_rhel_ipv6_normalize &&
+		    normalize_mailhost_addr(attr_value,
 					    &state->xforward.rfc_addr,
 					    &state->xforward.addr,
-					    NO_NORM_ADDR_FAMILY) < 0) {
+					    NO_NORM_ADDR_FAMILY) < 0) ||
+		    (!var_rhel_ipv6_normalize &&
+			(bare_value = valid_mailhost_addr(attr_value, DONT_GRIPE)) == 0)) {
 		    state->error_mask |= MAIL_ERROR_PROTOCOL;
 		    smtpd_chat_reply(state, "501 5.5.4 Bad %s syntax: %s",
 				     XFORWARD_ADDR, attr_value);
 		    return (-1);
 		}
+		if (!var_rhel_ipv6_normalize) {
+		    UPDATE_STR(state->xforward.addr, bare_value);
+		    UPDATE_STR(state->xforward.rfc_addr, attr_value);
+		}
 	    }
 	    break;