diff -ur sendmail-8.13.1-orig/sendmail/err.c sendmail-8.13.1-multiline/sendmail/err.c
--- sendmail-8.13.1-orig/sendmail/err.c	2003-01-09 21:16:46.000000000 -0500
+++ sendmail-8.13.1-multiline/sendmail/err.c	2004-10-26 07:46:09.000000000 -0400
@@ -620,11 +620,55 @@
 	/* if DisConnected, OutChannel now points to the transcript */
 	if (!DisConnected &&
 	    (OpMode == MD_SMTP || OpMode == MD_DAEMON || OpMode == MD_ARPAFTP))
+#if _FFR_MULTILINE_ERRORS
+	{
+		char msgcode[5];
+		char * msgbeg = msg + 4;
+		char * msg2 = NULL;
+		ssize_t msgsize = strlen(msgbeg);
+		
+		sm_strlcpy(msgcode, msg, sizeof(msgcode));
+		do
+		{
+			if ((msg2 = memchr((void*)msgbeg, '\n', msgsize)))
+			{
+				*msg2 = '\0';
+				msgsize -= (msg2 - msgbeg);
+				msgcode[3] = '-';
+			}
+			else
+				msgcode[3] = msg[3];
+			
+			(void) sm_io_fprintf(OutChannel, SM_TIME_DEFAULT, "%s%s\r\n",
+					     msgcode, msgbeg);
+			if (msg2)
+			{
+				*msg2 = ' '; 
+				msg2++;
+			}
+					
+		} while ((msgbeg = msg2) && (*msg2) && msgsize);
+	}
+	else
+	{
+		register int i = 0;
+		while (msg[i])
+		{
+			if(msg[i] == '\n')
+				msg[i] = ' ';
+			i++;
+		
+		}
+		(void) sm_io_fprintf(OutChannel, SM_TIME_DEFAULT, "%s\n",
+				     errtxt);
+	}
+#else
 		(void) sm_io_fprintf(OutChannel, SM_TIME_DEFAULT, "%s\r\n",
 				     msg);
 	else
 		(void) sm_io_fprintf(OutChannel, SM_TIME_DEFAULT, "%s\n",
 				     errtxt);
+#endif /* _FFR_MULTILINE_ERRORS */
 	if (TrafficLogFile != NULL)
 		(void) sm_io_fprintf(TrafficLogFile, SM_TIME_DEFAULT,
 				     "%05d >>> %s\n", (int) CurrentPid,
diff -ur sendmail-8.13.1-orig/sendmail/parseaddr.c sendmail-8.13.1-multiline/sendmail/parseaddr.c
--- sendmail-8.13.1-orig/sendmail/parseaddr.c	2004-05-18 16:01:54.000000000 -0400
+++ sendmail-8.13.1-multiline/sendmail/parseaddr.c	2004-10-26 07:41:31.000000000 -0400
@@ -2007,7 +2007,11 @@
 			a->q_host = NULL;
 			setstat(EX_UNAVAILABLE);
 		}
+#if _FFR_MULTILINE_ERRORS
+		convnlstring(ubuf);
+#endif /* _FFR_MULTILINE_ERRORS */
 		stripquotes(ubuf);
+		
 		if (ISSMTPCODE(ubuf) && ubuf[3] == ' ')
 		{
 			char fmt[16];
diff -ur sendmail-8.13.1-orig/sendmail/util.c sendmail-8.13.1-multiline/sendmail/util.c
--- sendmail-8.13.1-orig/sendmail/util.c	2004-03-26 14:01:10.000000000 -0500
+++ sendmail-8.13.1-multiline/sendmail/util.c	2004-10-26 07:41:31.000000000 -0400
@@ -2324,6 +2324,46 @@
 	return bp;
 }
 
+#if _FFR_MULTILINE_ERRORS
+/*
+** CONVNLSTRING -- Convert "\n" in string to '\n'. This is done in place.
+**
+** 	Parameters:
+** 		s -- string
+**	
+**	Returns:
+**
+**		nothing
+**
+**	Side effects:
+**		s now contains unquoted newline charachters
+**
+*/
+void
+convnlstring(s)
+	char *s;
+{
+	register char *p;
+	register char *q;
+	register char c;
+
+	if (s == NULL)
+		return;
+
+	p = q = s;
+	do
+	{
+		c = *p++;
+		if (c == '\\' && *p == 'n')
+		{
+			c = '\n';
+			p++;
+		}
+		*q++ = c;
+	} while (c != '\0');
+}
+#endif /* _FFR_MULTILINE_ERRORS */
+
 /*
 **  STRREPLNONPRT -- replace "unprintable" characters in a string with subst
 **