strncmp(num, "551", 3) != 0 && strncmp(num, "251", 3) != 0)
(strncmp(num, "050", 3) == 0 || strncmp(num, "250", 3) == 0 || strncmp(num, "252", 3) == 0 || strncmp(num, "450", 3) == 0 || strncmp(num, "550", 3) == 0 || strncmp(num, "553", 3) == 0))
fmtmsg(eb, to, num, enhsc, eno, fmt, ap)	register char *eb;	const char *to;	const char *num;	const char *enhsc;	int eno;	const char *fmt;	va_list ap;{	char del;	int l;	int spaceleft = sizeof MsgBuf;	char *errtxt;	/* output the reply code */	if (ISSMTPCODE(fmt))	{		num = fmt;		fmt += 4;	}	if (num[3] == '-')		del = '-';	else		del = ' ';	(void) snprintf(eb, spaceleft, "%3.3s%c", num, del);	eb += 4;	spaceleft -= 4;	if ((l = isenhsc(fmt, ' ' )) > 0 && l < spaceleft - 4)	{		/* copy enh.status code including trailing blank */		l++;		(void) strlcpy(eb, fmt, l + 1);		eb += l;		spaceleft -= l;		fmt += l;	}	else if ((l = isenhsc(enhsc, '\0')) > 0 && l < spaceleft - 4)	{		/* copy enh.status code */		(void) strlcpy(eb, enhsc, l + 1);		eb[l] = ' ';		eb[++l] = '\0';		eb += l;		spaceleft -= l;	}	errtxt = eb;	/* output the file name and line number */	if (FileName != NULL)	{		(void) snprintf(eb, spaceleft, "%s: line %d: ",			shortenstring(FileName, 83), LineNumber);		eb += (l = strlen(eb));		spaceleft -= l;	}	/* output the "to" person */	if (to != NULL && to[0] != '\0' &&	    strncmp(num, "551", 3) != 0 &&	    strncmp(num, "251", 3) != 0)	{		(void) snprintf(eb, spaceleft, "%s... ",			shortenstring(to, MAXSHORTSTR));		spaceleft -= strlen(eb);		while (*eb != '\0')			*eb++ &= 0177;	}	/* output the message */	(void) vsnprintf(eb, spaceleft, fmt, ap);	spaceleft -= strlen(eb);	while (*eb != '\0')		*eb++ &= 0177;	/* output the error code, if any */	if (eno != 0)		(void) snprintf(eb, spaceleft, ": %s", errstring(eno));	return errtxt;}