diff --git a/cf/cf/submit.mc b/cf/cf/submit.mc

index b9dfb16..cb325cc 100644

--- a/cf/cf/submit.mc

+++ b/cf/cf/submit.mc

@@ -22,6 +22,8 @@ define(`__OSTYPE__',`')dnl dirty hack to keep proto.m4 from complaining

 define(`_USE_DECNET_SYNTAX_', `1')dnl support DECnet

 define(`confTIME_ZONE', `USE_TZ')dnl

 define(`confDONT_INIT_GROUPS', `True')dnl

+dnl # If you're operating in a DSCP/RFC-4594 environment with QoS

+dnl define(`confINET_QOS', `AF11')dnl

 define(`confPID_FILE', `/run/sm-client.pid')dnl

 dnl define(`confDIRECT_SUBMISSION_MODIFIERS',`C')dnl

 FEATURE(`use_ct_file')dnl

diff --git a/cf/m4/proto.m4 b/cf/m4/proto.m4

index 5a5963b..0df3416 100644

--- a/cf/m4/proto.m4

+++ b/cf/m4/proto.m4

@@ -251,6 +251,9 @@ _OPTION(SevenBitInput, `confSEVEN_BIT_INPUT', `False')

 # 8-bit data handling

 _OPTION(EightBitMode, `confEIGHT_BIT_HANDLING', `pass8')

+# DSCP marking of traffic (IP_TOS)

+_OPTION(InetQoS, `confINET_QOS', `none')

+

 # wait for alias file rebuild (default units: minutes)

 _OPTION(AliasWait, `confALIAS_WAIT', `5m')

diff --git a/sendmail/conf.c b/sendmail/conf.c

index cbb9c76..1b55533 100644

--- a/sendmail/conf.c

+++ b/sendmail/conf.c

@@ -6430,6 +6430,10 @@ char	*FFRCompileOptions[] =

 #if _FFR_QF_PARANOIA

 	"_FFR_QF_PARANOIA",

 #endif

+#if _FFR_QOS && defined(SOL_IP) && defined(IP_TOS)

+	/* QoS */

+	"_FFR_QOS",

+#endif /* _FFR_QOS && defined(SOL_IP) && defined(IP_TOS) */

 #if _FFR_QUEUE_GROUP_SORTORDER

 	/* Allow QueueSortOrder per queue group. */

 /* XXX: Still need to actually use qgrp->qg_sortorder */

diff --git a/sendmail/daemon.c b/sendmail/daemon.c

index 4288365..86fe319 100644

--- a/sendmail/daemon.c

+++ b/sendmail/daemon.c

@@ -104,6 +104,10 @@ static int	NDaemons = 0;			/* actual number of daemons */

 static time_t	NextDiskSpaceCheck = 0;

+#if _FFR_QOS && defined(SOL_IP) && defined(IP_TOS)

+int		InetQoS = 0;			/* none by default */

+#endif /* _FFR_QOS && defined(SOL_IP) && defined(IP_TOS) */

+

 /*

 **  GETREQUESTS -- open mail IPC port and get requests.

 **

@@ -1139,6 +1143,16 @@ opendaemonsocket(d, firsttime)

 			(void) setsockopt(d->d_socket, SOL_SOCKET,

 					  SO_KEEPALIVE, (char *)&on, sizeof(on));

+#if _FFR_QOS && defined(SOL_IP) && defined(IP_TOS)

+			if (InetQoS != 0x00

+			 && (d->d_addr.sa.sa_family == AF_INET

+			  || (d->d_addr.sin6.sin6_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(d->d_addr.sin6.sin6_addr.s6_addr32)))) {

+				if (setsockopt(d->d_socket, SOL_IP,

+						  IP_TOS, (char *)&InetQoS, sizeof(InetQoS)) < 0)

+					syserr("opendaemonsock: daemon %s: setsockopt(IP_TOS)", d->d_name);

+			}

+#endif /* _FFR_QOS && defined(SOL_IP) && defined(IP_TOS) */

+

 #ifdef SO_RCVBUF

 			if (d->d_tcprcvbufsize > 0)

 			{

@@ -2571,6 +2585,16 @@ gothostent:

 			return EX_TEMPFAIL;

 		}

+#if _FFR_QOS && defined(SOL_IP) && defined(IP_TOS)

+		if (InetQoS != 0x00

+		 && (family == AF_INET

+		  || (family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(addr.sin6.sin6_addr.s6_addr32))))

+		{

+			if (setsockopt(s, SOL_IP, IP_TOS,

+					  (char *)&InetQoS, sizeof(InetQoS)) < 0)

+				syserr("makeconnection: setsockopt(IP_TOS)");

+		}

+#endif /* _FFR_QOS && defined(SOL_IP) && defined(IP_TOS) */

 #ifdef SO_SNDBUF

 		if (ClientSettings[family].d_tcpsndbufsize > 0)

 		{

diff --git a/sendmail/readcf.c b/sendmail/readcf.c

index 2b0fbf7..86892f5 100644

--- a/sendmail/readcf.c

+++ b/sendmail/readcf.c

@@ -18,6 +18,7 @@ SM_RCSID("@(#)$Id: readcf.c,v 8.692 2013-11-22 20:51:56 ca Exp $")

 #if NETINET || NETINET6

 # include <arpa/inet.h>

+# include <netinet/ip.h>

 #endif /* NETINET || NETINET6 */

@@ -2888,8 +2889,8 @@ static struct optioninfo

 # define O_RCPTTHROTDELAY	0xe6

 	{ "BadRcptThrottleDelay",	O_RCPTTHROTDELAY,	OI_SAFE	},

 #endif /* _FFR_RCPTTHROTDELAY */

-#if 0 && _FFR_QOS && defined(SOL_IP) && defined(IP_TOS)

-# define O_INETQOS	0xe7	/* reserved for FFR_QOS */

+#if _FFR_QOS && defined(SOL_IP) && defined(IP_TOS)

+# define O_INETQOS		0xe7

 	{ "InetQoS",			O_INETQOS,	OI_NONE },

 #endif

 #if STARTTLS && _FFR_FIPSMODE

@@ -2914,6 +2915,77 @@ static struct optioninfo

 	{ NULL,				'\0',		OI_NONE	}

 };

+#ifdef O_INETQOS

+static struct qosmap

+{

+	char	*name;		/* name of the setting */

+	int	value;		/* corresponding setsockopt() value */

+} QoSMap[] = {

+#ifdef IPTOS_CLASS_CS0

+	{ "CS0",	IPTOS_CLASS_CS0 },

+#endif

+#ifdef IPTOS_CLASS_CS1

+	{ "CS1",	IPTOS_CLASS_CS1 },

+#endif

+#ifdef IPTOS_DSCP_AF11

+	{ "AF11",	IPTOS_DSCP_AF11 },

+#endif

+#ifdef IPTOS_DSCP_AF12

+	{ "AF12",	IPTOS_DSCP_AF12 },

+#endif

+#ifdef IPTOS_DSCP_AF13

+	{ "AF13",	IPTOS_DSCP_AF13 },

+#endif

+#ifdef IPTOS_CLASS_CS2

+	{ "CS2",	IPTOS_CLASS_CS2 },

+#endif

+#ifdef IPTOS_DSCP_AF21

+	{ "AF21",	IPTOS_DSCP_AF21 },

+#endif

+#ifdef IPTOS_DSCP_AF22

+	{ "AF22",	IPTOS_DSCP_AF22 },

+#endif

+#ifdef IPTOS_DSCP_AF23

+	{ "AF23",	IPTOS_DSCP_AF23 },

+#endif

+#ifdef IPTOS_CLASS_CS3

+	{ "CS3",	IPTOS_CLASS_CS3 },

+#endif

+#ifdef IPTOS_DSCP_AF31

+	{ "AF31",	IPTOS_DSCP_AF31 },

+#endif

+#ifdef IPTOS_DSCP_AF32

+	{ "AF32",	IPTOS_DSCP_AF32 },

+#endif

+#ifdef IPTOS_DSCP_AF33

+	{ "AF33",	IPTOS_DSCP_AF33 },

+#endif

+#ifdef IPTOS_CLASS_CS4

+	{ "CS4",	IPTOS_CLASS_CS4 },

+#endif

+#ifdef IPTOS_DSCP_AF41

+	{ "AF41",	IPTOS_DSCP_AF41 },

+#endif

+#ifdef IPTOS_DSCP_AF42

+	{ "AF42",	IPTOS_DSCP_AF42 },

+#endif

+#ifdef IPTOS_DSCP_AF43

+	{ "AF43",	IPTOS_DSCP_AF43 },

+#endif

+#ifdef IPTOS_CLASS_CS5

+	{ "CS5",	IPTOS_CLASS_CS5 },

+#endif

+#ifdef IPTOS_CLASS_CS6

+	{ "CS6",	IPTOS_CLASS_CS6 },

+#endif

+#ifdef IPTOS_CLASS_CS7

+	{ "CS7",	IPTOS_CLASS_CS7 },

+#endif

+	{ "none",	0x00 },

+	{ NULL,		0    }

+};

+#endif

+

 # define CANONIFY(val)

 # define SET_OPT_DEFAULT(opt, val)	opt = val

@@ -4540,6 +4612,33 @@ setoption(opt, val, safe, sticky, e)

 		UseCompressedIPv6Addresses = atobool(val);

 		break;

+#ifdef O_INETQOS

+	  case O_INETQOS:

+		{

+			struct qosmap *qmp;

+			InetQoS = -1;

+

+			for (qmp = QoSMap; qmp->name != NULL; ++qmp) {

+				if (!strcmp(val, qmp->name)) {

+					InetQoS = qmp->value;

+					break;

+				}

+			}

+

+			/*

+			** we could allow writing it as a hex value, but

+			** we don't at this time.

+			**/

+			if (qmp->name == NULL) {

+				(void) sm_io_fprintf(smioout, SM_TIME_DEFAULT,

+						     "Warning: Option: %s unknown parameter '%s'\n",

+						     OPTNAME, val);

+				break;

+			}

+			break;

+		}

+#endif

+

 	  default:

 		if (tTd(37, 1))

 		{

diff --git a/sendmail/sendmail.h b/sendmail/sendmail.h

index b2d0211..3bcc2e2 100644

--- a/sendmail/sendmail.h

+++ b/sendmail/sendmail.h

@@ -2537,7 +2537,14 @@ EXTERN struct termescape	TermEscape;	/* terminal escape codes */

 EXTERN SOCKADDR	ConnectOnlyTo;	/* override connection address (for testing) */

 EXTERN SOCKADDR RealHostAddr;	/* address of host we are talking to */

 extern const SM_EXC_TYPE_T EtypeQuickAbort; /* type of a QuickAbort exception */

-

+#if _FFR_QOS

+# if !defined(SOL_IP) && defined(IPPROTO_IP)

+#  define SOL_IP IPPROTO_IP

+# endif

+# if defined(SOL_IP) && defined(IP_TOS)

+EXTERN int	InetQoS;	/* QoS mapping */

+# endif

+#endif

 EXTERN int ConnectionRateWindowSize;

 #if STARTTLS && USE_OPENSSL_ENGINE