www.gusucode.com > VC++版的邮件服务器源程序源码程序 > VC++版的邮件服务器源程序源码程序\code\SMTPUtils.cpp

    //Download by http://www.NewXing.com
/*
 *  XMail by Davide Libenzi ( Intranet and Internet mail server )
 *  Copyright (C) 1999,..,2004  Davide Libenzi
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *  Davide Libenzi <davidel@xmailserver.org>
 *
 */

#include "SysInclude.h"
#include "SysDep.h"
#include "SvrDefines.h"
#include "ShBlocks.h"
#include "ResLocks.h"
#include "StrUtils.h"
#include "SList.h"
#include "BuffSock.h"
#include "MailConfig.h"
#include "UsrUtils.h"
#include "UsrAuth.h"
#include "SvrUtils.h"
#include "MiscUtils.h"
#include "DNS.h"
#include "DNSCache.h"
#include "MessQueue.h"
#include "SMAILUtils.h"
#include "QueueUtils.h"
#include "SMTPSvr.h"
#include "SMTPUtils.h"
#include "Base64Enc.h"
#include "MD5.h"
#include "MailSvr.h"

#define STD_SMTP_TIMEOUT        STD_SERVER_TIMEOUT
#define SMTPGW_LINE_MAX         1024
#define SMTPGW_TABLE_FILE       "smtpgw.tab"
#define SMTPFWD_LINE_MAX        1024
#define SMTPFWD_TABLE_FILE      "smtpfwd.tab"
#define SMTPRELAY_LINE_MAX      512
#define SMTP_RELAY_FILE         "smtprelay.tab"
#define MAX_MX_RECORDS          32
#define SMTP_SPAMMERS_FILE      "spammers.tab"
#define SMTP_SPAM_ADDRESS_FILE  "spam-address.tab"
#define SPAMMERS_LINE_MAX       512
#define SPAM_ADDRESS_LINE_MAX   512
#define SMTPAUTH_LINE_MAX       512
#define SMTP_EXTAUTH_TIMEOUT    60
#define SMTP_EXTAUTH_PRIORITY   SYS_PRIORITY_NORMAL
#define SMTP_EXTAUTH_SUCCESS    0
#define RFC_SPECIALS            "()<>@,/\\;:\"[]*?"

#define SMTPCH_SUPPORT_SIZE     (1 << 0)

enum SmtpGwFileds {
	gwDomain = 0,
	gwGateway,

	gwMax
};

enum SmtpFwdFileds {
	fwdDomain = 0,
	fwdGateway,

	fwdMax
};

enum SmtpRelayFileds {
	rlyFromIP = 0,
	rlyFromMask,

	rlyMax
};

enum SpammerFileds {
	spmFromIP = 0,
	spmFromMask,

	spmMax
};

struct SmtpMXRecords {
	int iNumMXRecords;
	int iMXCost[MAX_MX_RECORDS];
	char *pszMXName[MAX_MX_RECORDS];
	int iCurrMxCost;
};

struct SmtpChannel {
	BSOCK_HANDLE hBSock;
	unsigned long ulFlags;
	unsigned long ulMaxMsgSize;
	SYS_INET_ADDR SvrAddr;
	char *pszServer;
};

static int USmtpWriteGateway(FILE * pGwFile, const char *pszDomain, const char *pszGateway);
static char *USmtpGetGwTableFilePath(char *pszGwFilePath, int iMaxPath);
static char *USmtpGetFwdTableFilePath(char *pszFwdFilePath, int iMaxPath);
static char *USmtpGetRelayFilePath(char *pszRelayFilePath, int iMaxPath);
static int USmtpSetError(SMTPError * pSMTPE, int iSTMPResponse, char const *pszSTMPResponse,
			 char const *pszServer);
static int USmtpSetErrorServer(SMTPError * pSMTPE, char const *pszServer);
static int USmtpResponseClass(int iResponseCode, int iResponseClass);
static int USmtpGetResultCode(const char *pszResult);
static int USmtpIsPartialResponse(char const *pszResponse);
static int USmtpGetResponse(BSOCK_HANDLE hBSock, char *pszResponse, int iMaxResponse,
			    int iTimeout = STD_SMTP_TIMEOUT);
static int USmtpSendCommand(BSOCK_HANDLE hBSock, const char *pszCommand,
			    char *pszResponse, int iMaxResponse, int iTimeout = STD_SMTP_TIMEOUT);
static int USmtpGetServerAuthFile(char const *pszServer, char *pszAuthFilePath);
static int USmtpDoPlainAuth(SmtpChannel * pSmtpCh, char const *pszServer,
			    char const *const *ppszAuthTokens, SMTPError * pSMTPE);
static int USmtpDoLoginAuth(SmtpChannel * pSmtpCh, char const *pszServer,
			    char const *const *ppszAuthTokens, SMTPError * pSMTPE);
static int USmtpDoCramMD5Auth(SmtpChannel * pSmtpCh, char const *pszServer,
			      char const *const *ppszAuthTokens, SMTPError * pSMTPE);
static int USmtpExternalAuthSubstitute(char **ppszAuthTokens, char const *pszChallenge,
				       char const *pszSecret, char const *pszRespFile);
static int USmtpDoExternAuth(SmtpChannel * pSmtpCh, char const *pszServer,
			     char **ppszAuthTokens, SMTPError * pSMTPE);
static int USmtpServerAuthenticate(SmtpChannel * pSmtpCh, char const *pszServer,
				   SMTPError * pSMTPE);
static int USmtpParseEhloResponse(SmtpChannel * pSmtpCh, char const *pszResponse);
static int USmtpGetDomainMX(SVRCFG_HANDLE hSvrConfig, const char *pszDomain, char *&pszMXDomains);
static char *USmtpGetSpammersFilePath(char *pszSpamFilePath, int iMaxPath);
static char *USmtpGetSpamAddrFilePath(char *pszSpamFilePath, int iMaxPath);

static char *USmtpGetGwTableFilePath(char *pszGwFilePath, int iMaxPath)
{

	CfgGetRootPath(pszGwFilePath, iMaxPath);

	StrNCat(pszGwFilePath, SMTPGW_TABLE_FILE, iMaxPath);

	return (pszGwFilePath);

}

static char *USmtpGetFwdTableFilePath(char *pszFwdFilePath, int iMaxPath)
{

	CfgGetRootPath(pszFwdFilePath, iMaxPath);

	StrNCat(pszFwdFilePath, SMTPFWD_TABLE_FILE, iMaxPath);

	return (pszFwdFilePath);

}

char **USmtpGetFwdGateways(SVRCFG_HANDLE hSvrConfig, const char *pszDomain)
{

	char szFwdFilePath[SYS_MAX_PATH] = "";

	USmtpGetFwdTableFilePath(szFwdFilePath, sizeof(szFwdFilePath));

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockSH(CfgGetBasedPath(szFwdFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (NULL);

	FILE *pFwdFile = fopen(szFwdFilePath, "rt");

	if (pFwdFile == NULL) {
		RLckUnlockSH(hResLock);

		ErrSetErrorCode(ERR_SMTPFWD_FILE_NOT_FOUND);
		return (NULL);
	}

	char szFwdLine[SMTPFWD_LINE_MAX] = "";

	while (MscGetConfigLine(szFwdLine, sizeof(szFwdLine) - 1, pFwdFile) != NULL) {
		char **ppszStrings = StrGetTabLineStrings(szFwdLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);

		if ((iFieldsCount >= fwdMax) && StrIWildMatch(pszDomain, ppszStrings[fwdDomain])) {
			char **ppszFwdGws = NULL;

			if (ppszStrings[fwdGateway][0] == '#') {
				if ((ppszFwdGws =
				     StrTokenize(ppszStrings[fwdGateway] + 1, ",")) != NULL) {
					int iGwCount = StrStringsCount(ppszFwdGws);

					srand((unsigned int) time(NULL));

					for (int ii = 0; ii < (iGwCount / 2); ii++) {
						int iSwap1 = rand() % iGwCount;
						int iSwap2 = rand() % iGwCount;
						char *pszGw1 = ppszFwdGws[iSwap1];
						char *pszGw2 = ppszFwdGws[iSwap2];

						ppszFwdGws[iSwap1] = pszGw2;
						ppszFwdGws[iSwap2] = pszGw1;
					}
				}
			} else
				ppszFwdGws = StrTokenize(ppszStrings[fwdGateway], ",");

			StrFreeStrings(ppszStrings);
			fclose(pFwdFile);

			RLckUnlockSH(hResLock);

			return (ppszFwdGws);
		}

		StrFreeStrings(ppszStrings);
	}

	fclose(pFwdFile);

	RLckUnlockSH(hResLock);

	ErrSetErrorCode(ERR_SMTPFWD_NOT_FOUND);
	return (NULL);

}

static char *USmtpGetRelayFilePath(char *pszRelayFilePath, int iMaxPath)
{

	CfgGetRootPath(pszRelayFilePath, iMaxPath);

	StrNCat(pszRelayFilePath, SMTP_RELAY_FILE, iMaxPath);

	return (pszRelayFilePath);

}

int USmtpGetGateway(SVRCFG_HANDLE hSvrConfig, const char *pszDomain, char *pszGateway)
{

	char szGwFilePath[SYS_MAX_PATH] = "";

	USmtpGetGwTableFilePath(szGwFilePath, sizeof(szGwFilePath));

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockSH(CfgGetBasedPath(szGwFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (ErrGetErrorCode());

	FILE *pGwFile = fopen(szGwFilePath, "rt");

	if (pGwFile == NULL) {
		RLckUnlockSH(hResLock);

		ErrSetErrorCode(ERR_SMTPGW_FILE_NOT_FOUND);
		return (ERR_SMTPGW_FILE_NOT_FOUND);
	}

	char szGwLine[SMTPGW_LINE_MAX] = "";

	while (MscGetConfigLine(szGwLine, sizeof(szGwLine) - 1, pGwFile) != NULL) {
		char **ppszStrings = StrGetTabLineStrings(szGwLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);

		if ((iFieldsCount >= gwMax) && StrIWildMatch(pszDomain, ppszStrings[gwDomain])) {
			strcpy(pszGateway, ppszStrings[gwGateway]);

			StrFreeStrings(ppszStrings);
			fclose(pGwFile);

			RLckUnlockSH(hResLock);

			return (0);
		}

		StrFreeStrings(ppszStrings);
	}

	fclose(pGwFile);

	RLckUnlockSH(hResLock);

	ErrSetErrorCode(ERR_SMTPGW_NOT_FOUND);
	return (ERR_SMTPGW_NOT_FOUND);

}

static int USmtpWriteGateway(FILE * pGwFile, const char *pszDomain, const char *pszGateway)
{

///////////////////////////////////////////////////////////////////////////////
//  Domain
///////////////////////////////////////////////////////////////////////////////
	char *pszQuoted = StrQuote(pszDomain, '"');

	if (pszQuoted == NULL)
		return (ErrGetErrorCode());

	fprintf(pGwFile, "%s\t", pszQuoted);

	SysFree(pszQuoted);

///////////////////////////////////////////////////////////////////////////////
//  Gateway
///////////////////////////////////////////////////////////////////////////////
	pszQuoted = StrQuote(pszGateway, '"');

	if (pszQuoted == NULL)
		return (ErrGetErrorCode());

	fprintf(pGwFile, "%s\n", pszQuoted);

	SysFree(pszQuoted);

	return (0);

}

int USmtpAddGateway(const char *pszDomain, const char *pszGateway)
{

	char szGwFilePath[SYS_MAX_PATH] = "";

	USmtpGetGwTableFilePath(szGwFilePath, sizeof(szGwFilePath));

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockEX(CfgGetBasedPath(szGwFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (ErrGetErrorCode());

	FILE *pGwFile = fopen(szGwFilePath, "r+t");

	if (pGwFile == NULL) {
		RLckUnlockEX(hResLock);

		ErrSetErrorCode(ERR_SMTPGW_FILE_NOT_FOUND);
		return (ERR_SMTPGW_FILE_NOT_FOUND);
	}

	char szGwLine[SMTPGW_LINE_MAX] = "";

	while (MscGetConfigLine(szGwLine, sizeof(szGwLine) - 1, pGwFile) != NULL) {
		char **ppszStrings = StrGetTabLineStrings(szGwLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);

		if ((iFieldsCount >= gwMax) && (stricmp(pszDomain, ppszStrings[gwDomain]) == 0) &&
		    (stricmp(pszGateway, ppszStrings[gwGateway]) == 0)) {
			StrFreeStrings(ppszStrings);
			fclose(pGwFile);
			RLckUnlockEX(hResLock);

			ErrSetErrorCode(ERR_GATEWAY_ALREADY_EXIST);
			return (ERR_GATEWAY_ALREADY_EXIST);
		}

		StrFreeStrings(ppszStrings);
	}

	fseek(pGwFile, 0, SEEK_END);

	if (USmtpWriteGateway(pGwFile, pszDomain, pszGateway) < 0) {
		fclose(pGwFile);
		RLckUnlockEX(hResLock);
		return (ErrGetErrorCode());
	}

	fclose(pGwFile);

	RLckUnlockEX(hResLock);

	return (0);

}

int USmtpRemoveGateway(const char *pszDomain)
{

	char szGwFilePath[SYS_MAX_PATH] = "";

	USmtpGetGwTableFilePath(szGwFilePath, sizeof(szGwFilePath));

	char szTmpFile[SYS_MAX_PATH] = "";

	SysGetTmpFile(szTmpFile);

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockEX(CfgGetBasedPath(szGwFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (ErrGetErrorCode());

	FILE *pGwFile = fopen(szGwFilePath, "rt");

	if (pGwFile == NULL) {
		RLckUnlockEX(hResLock);

		ErrSetErrorCode(ERR_SMTPGW_FILE_NOT_FOUND);
		return (ERR_SMTPGW_FILE_NOT_FOUND);
	}

	FILE *pTmpFile = fopen(szTmpFile, "wt");

	if (pTmpFile == NULL) {
		fclose(pGwFile);
		RLckUnlockEX(hResLock);

		ErrSetErrorCode(ERR_FILE_CREATE);
		return (ERR_FILE_CREATE);
	}

	int iGatewayFound = 0;
	char szGwLine[SMTPGW_LINE_MAX] = "";

	while (MscGetConfigLine(szGwLine, sizeof(szGwLine) - 1, pGwFile, false) != NULL) {
		if (szGwLine[0] == TAB_COMMENT_CHAR) {
			fprintf(pTmpFile, "%s\n", szGwLine);
			continue;
		}

		char **ppszStrings = StrGetTabLineStrings(szGwLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);

		if ((iFieldsCount >= gwMax) && (stricmp(pszDomain, ppszStrings[gwDomain]) == 0)) {

			++iGatewayFound;

		} else
			fprintf(pTmpFile, "%s\n", szGwLine);

		StrFreeStrings(ppszStrings);
	}

	fclose(pGwFile);
	fclose(pTmpFile);

	if (iGatewayFound == 0) {
		SysRemove(szTmpFile);
		RLckUnlockEX(hResLock);

		ErrSetErrorCode(ERR_GATEWAY_NOT_FOUND);
		return (ERR_GATEWAY_NOT_FOUND);
	}

	char szTmpGwFilePath[SYS_MAX_PATH] = "";

	sprintf(szTmpGwFilePath, "%s.tmp", szGwFilePath);

	if (MscMoveFile(szGwFilePath, szTmpGwFilePath) < 0) {
		ErrorPush();
		RLckUnlockEX(hResLock);
		return (ErrorPop());
	}

	if (MscMoveFile(szTmpFile, szGwFilePath) < 0) {
		ErrorPush();
		MscMoveFile(szTmpGwFilePath, szGwFilePath);
		RLckUnlockEX(hResLock);
		return (ErrorPop());
	}

	SysRemove(szTmpGwFilePath);

	RLckUnlockEX(hResLock);

	return (0);

}

int USmtpIsAllowedRelay(const SYS_INET_ADDR & PeerInfo, SVRCFG_HANDLE hSvrConfig)
{

	char szRelayFilePath[SYS_MAX_PATH] = "";

	USmtpGetRelayFilePath(szRelayFilePath, sizeof(szRelayFilePath));

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockSH(CfgGetBasedPath(szRelayFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (ErrGetErrorCode());

	FILE *pRelayFile = fopen(szRelayFilePath, "rt");

	if (pRelayFile == NULL) {
		RLckUnlockSH(hResLock);

		ErrSetErrorCode(ERR_SMTPRELAY_FILE_NOT_FOUND);
		return (ERR_SMTPRELAY_FILE_NOT_FOUND);
	}

	NET_ADDRESS TestAddr;

	SysGetAddrAddress(PeerInfo, TestAddr);

	char szRelayLine[SMTPRELAY_LINE_MAX] = "";

	while (MscGetConfigLine(szRelayLine, sizeof(szRelayLine) - 1, pRelayFile) != NULL) {
		char **ppszStrings = StrGetTabLineStrings(szRelayLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);
		AddressFilter AF;

		if ((iFieldsCount > 0) &&
		    (MscLoadAddressFilter(ppszStrings, iFieldsCount, AF) == 0) &&
		    MscAddressMatch(AF, TestAddr)) {
			StrFreeStrings(ppszStrings);
			fclose(pRelayFile);
			RLckUnlockSH(hResLock);

			return (0);
		}

		StrFreeStrings(ppszStrings);
	}

	fclose(pRelayFile);

	RLckUnlockSH(hResLock);

	ErrSetErrorCode(ERR_RELAY_NOT_ALLOWED);

	return (ERR_RELAY_NOT_ALLOWED);

}

char **USmtpGetPathStrings(const char *pszMailCmd)
{

	const char *pszOpen = strchr(pszMailCmd, '<');
	const char *pszClose = strchr(pszMailCmd, '>');

	if ((pszOpen == NULL) || (pszClose == NULL)) {
		ErrSetErrorCode(ERR_SMTP_PATH_PARSE_ERROR);
		return (NULL);
	}

	int iPathLength = (int) (pszClose - pszOpen) - 1;

	if ((iPathLength < 0) || (iPathLength >= MAX_SMTP_ADDRESS)) {
		ErrSetErrorCode(ERR_SMTP_PATH_PARSE_ERROR, pszMailCmd);
		return (NULL);
	}

	char *pszPath = (char *) SysAlloc(iPathLength + 1);

	if (pszPath == NULL)
		return (NULL);

	strncpy(pszPath, pszOpen + 1, iPathLength);
	pszPath[iPathLength] = '\0';

	char **ppszDomains = StrTokenize(pszPath, ",:");

	SysFree(pszPath);

	return (ppszDomains);

}

int USmtpSplitEmailAddr(const char *pszAddr, char *pszUser, char *pszDomain)
{

	const char *pszAT = strchr(pszAddr, '@');

	if (pszAT == NULL) {
		ErrSetErrorCode(ERR_BAD_EMAIL_ADDR);
		return (ERR_BAD_EMAIL_ADDR);
	}

	int iUserLength = (int) (pszAT - pszAddr);
	int iDomainLength = strlen(pszAT + 1);

	if (pszUser != NULL) {
		if (iUserLength == 0) {
			ErrSetErrorCode(ERR_BAD_EMAIL_ADDR);
			return (ERR_BAD_EMAIL_ADDR);
		}

		iUserLength = Min(iUserLength, MAX_ADDR_NAME - 1);
		strncpy(pszUser, pszAddr, iUserLength);
		pszUser[iUserLength] = '\0';
	}

	if (pszDomain != NULL) {
		if (iDomainLength == 0) {
			ErrSetErrorCode(ERR_BAD_EMAIL_ADDR);
			return (ERR_BAD_EMAIL_ADDR);
		}

		StrNCpy(pszDomain, pszAT + 1, MAX_ADDR_NAME);
	}

	return (0);

}

int USmtpCheckAddressPart(char const *pszName)
{

	for (; *pszName; pszName++)
		if ((*pszName <= ' ') || (*pszName == 127) ||
		    (strchr(RFC_SPECIALS, *pszName) != NULL)) {
			ErrSetErrorCode(ERR_BAD_RFCNAME);
			return (ERR_BAD_RFCNAME);
		}

	return (0);

}

int USmtpCheckAddress(char const *pszAddress)
{
	char szUser[MAX_ADDR_NAME] = "";
	char szDomain[MAX_ADDR_NAME] = "";

	if ((USmtpSplitEmailAddr(pszAddress, szUser, szDomain) < 0) ||
	    (USmtpCheckAddressPart(szUser) < 0) || (USmtpCheckAddressPart(szDomain) < 0))
		return (ErrGetErrorCode());

	return (0);

}

int USmtpInitError(SMTPError * pSMTPE)
{

	ZeroData(*pSMTPE);
	pSMTPE->iSTMPResponse = 0;
	pSMTPE->pszSTMPResponse = NULL;
	pSMTPE->pszServer = NULL;

	return (0);

}

static int USmtpSetError(SMTPError * pSMTPE, int iSTMPResponse, char const *pszSTMPResponse,
			 char const *pszServer)
{

	pSMTPE->iSTMPResponse = iSTMPResponse;

	if (pSMTPE->pszSTMPResponse != NULL)
		SysFree(pSMTPE->pszSTMPResponse);

	if (pSMTPE->pszServer != NULL)
		SysFree(pSMTPE->pszServer);

	pSMTPE->pszSTMPResponse = SysStrDup(pszSTMPResponse);
	pSMTPE->pszServer = SysStrDup(pszServer);

	return (0);

}

static int USmtpSetErrorServer(SMTPError * pSMTPE, char const *pszServer)
{

	if (pSMTPE->pszServer != NULL)
		SysFree(pSMTPE->pszServer);

	pSMTPE->pszServer = SysStrDup(pszServer);

	return (0);

}

bool USmtpIsFatalError(SMTPError const *pSMTPE)
{

	return ((pSMTPE->iSTMPResponse == SMTP_FATAL_ERROR) ||
		((pSMTPE->iSTMPResponse >= 500) && (pSMTPE->iSTMPResponse < 600)));

}

char const *USmtpGetErrorMessage(SMTPError const *pSMTPE)
{

	return ((pSMTPE->pszSTMPResponse != NULL) ? pSMTPE->pszSTMPResponse : "");

}

int USmtpCleanupError(SMTPError * pSMTPE)
{

	if (pSMTPE->pszSTMPResponse != NULL)
		SysFree(pSMTPE->pszSTMPResponse);

	if (pSMTPE->pszServer != NULL)
		SysFree(pSMTPE->pszServer);

	USmtpInitError(pSMTPE);

	return (0);

}

char *USmtpGetSMTPError(SMTPError * pSMTPE, char *pszError, int iMaxError)
{

	char const *pszSmtpErr =
	    (pSMTPE != NULL) ? USmtpGetErrorMessage(pSMTPE) : DEFAULT_SMTP_ERR;

	if (IsEmptyString(pszSmtpErr))
		pszSmtpErr = DEFAULT_SMTP_ERR;

	StrNCpy(pszError, pszSmtpErr, iMaxError);

	return (pszError);

}

char const *USmtpGetErrorServer(SMTPError const *pSMTPE)
{

	return ((pSMTPE->pszServer != NULL) ? pSMTPE->pszServer : "");

}

static int USmtpResponseClass(int iResponseCode, int iResponseClass)
{

	return (((iResponseCode >= iResponseClass) &&
		 (iResponseCode < (iResponseClass + 100))) ? 1 : 0);

}

static int USmtpGetResultCode(const char *pszResult)
{

	int ii;
	char szResCode[64] = "";

	for (ii = 0; isdigit(pszResult[ii]); ii++)
		szResCode[ii] = pszResult[ii];

	szResCode[ii] = '\0';

	if (ii == 0) {
		ErrSetErrorCode(ERR_BAD_SMTP_RESPONSE);
		return (ERR_BAD_SMTP_RESPONSE);
	}

	return (atoi(szResCode));

}

static int USmtpIsPartialResponse(char const *pszResponse)
{

	return (((strlen(pszResponse) >= 4) && (pszResponse[3] == '-')) ? 1 : 0);

}

static int USmtpGetResponse(BSOCK_HANDLE hBSock, char *pszResponse, int iMaxResponse,
			    int iTimeout)
{

	int iResultCode = -1;
	int iResponseLenght = 0;
	char szPartial[1024] = "";

	SetEmptyString(pszResponse);
	do {
		int iLineLength = 0;

		if (BSckGetString(hBSock, szPartial, sizeof(szPartial) - 1, iTimeout,
				  &iLineLength) == NULL)
			return (ErrGetErrorCode());

		if ((iResponseLenght + 2) < iMaxResponse) {
			if (iResponseLenght > 0)
				strcat(pszResponse, "\r\n"), iResponseLenght += 2;

			int iCopyLenght = Min(iMaxResponse - 1 - iResponseLenght, iLineLength);

			if (iCopyLenght > 0) {
				strncpy(pszResponse + iResponseLenght, szPartial, iCopyLenght);

				iResponseLenght += iCopyLenght;

				pszResponse[iResponseLenght] = '\0';
			}
		}

		if ((iResultCode = USmtpGetResultCode(szPartial)) < 0)
			return (ErrGetErrorCode());

	} while (USmtpIsPartialResponse(szPartial));

	return (iResultCode);

}

static int USmtpSendCommand(BSOCK_HANDLE hBSock, const char *pszCommand,
			    char *pszResponse, int iMaxResponse, int iTimeout)
{

	if (BSckSendString(hBSock, pszCommand, iTimeout) <= 0)
		return (ErrGetErrorCode());

	return (USmtpGetResponse(hBSock, pszResponse, iMaxResponse, iTimeout));

}

static int USmtpGetServerAuthFile(char const *pszServer, char *pszAuthFilePath)
{

	int iRootedName = MscRootedName(pszServer);
	char szAuthPath[SYS_MAX_PATH] = "";

	UAthGetRootPath(AUTH_SERVICE_SMTP, szAuthPath, sizeof(szAuthPath));

	char const *pszDot = pszServer;

	while ((pszDot != NULL) && (strlen(pszDot) > 0)) {
		if (iRootedName)
			sprintf(pszAuthFilePath, "%s%stab", szAuthPath, pszDot);
		else
			sprintf(pszAuthFilePath, "%s%s.tab", szAuthPath, pszDot);

		if (SysExistFile(pszAuthFilePath))
			return (0);

		if ((pszDot = strchr(pszDot, '.')) != NULL)
			++pszDot;
	}

	ErrSetErrorCode(ERR_NO_SMTP_AUTH_CONFIG);
	return (ERR_NO_SMTP_AUTH_CONFIG);

}

static int USmtpDoPlainAuth(SmtpChannel * pSmtpCh, char const *pszServer,
			    char const *const *ppszAuthTokens, SMTPError * pSMTPE)
{

	if (StrStringsCount(ppszAuthTokens) < 3) {
		ErrSetErrorCode(ERR_BAD_SMTP_AUTH_CONFIG);
		return (ERR_BAD_SMTP_AUTH_CONFIG);
	}
///////////////////////////////////////////////////////////////////////////////
//  Build plain text authentication token ( "\0" Username "\0" Password "\0" )
///////////////////////////////////////////////////////////////////////////////
	int iAuthLength = 1;
	char szAuthBuffer[2048] = "";

	strcpy(szAuthBuffer + iAuthLength, ppszAuthTokens[1]);
	iAuthLength += strlen(ppszAuthTokens[1]) + 1;

	strcpy(szAuthBuffer + iAuthLength, ppszAuthTokens[2]);
	iAuthLength += strlen(ppszAuthTokens[2]);

	unsigned int uEnc64Length = 0;
	char szEnc64Token[1024] = "";

	encode64(szAuthBuffer, iAuthLength, szEnc64Token, sizeof(szEnc64Token), &uEnc64Length);

///////////////////////////////////////////////////////////////////////////////
//  Send AUTH command
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse;

	SysSNPrintf(szAuthBuffer, sizeof(szAuthBuffer) - 1, "AUTH PLAIN %s", szEnc64Token);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}

	return (0);

}

static int USmtpDoLoginAuth(SmtpChannel * pSmtpCh, char const *pszServer,
			    char const *const *ppszAuthTokens, SMTPError * pSMTPE)
{

	if (StrStringsCount(ppszAuthTokens) < 3) {
		ErrSetErrorCode(ERR_BAD_SMTP_AUTH_CONFIG);
		return (ERR_BAD_SMTP_AUTH_CONFIG);
	}
///////////////////////////////////////////////////////////////////////////////
//  Send AUTH command
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse;
	char szAuthBuffer[1024] = "";

	sprintf(szAuthBuffer, "AUTH LOGIN");

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 300)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Send username
///////////////////////////////////////////////////////////////////////////////
	unsigned int uEnc64Length = 0;

	encode64(ppszAuthTokens[1], strlen(ppszAuthTokens[1]), szAuthBuffer,
		 sizeof(szAuthBuffer), &uEnc64Length);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 300)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Send password
///////////////////////////////////////////////////////////////////////////////
	encode64(ppszAuthTokens[2], strlen(ppszAuthTokens[2]), szAuthBuffer,
		 sizeof(szAuthBuffer), &uEnc64Length);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}

	return (0);

}

static int USmtpDoCramMD5Auth(SmtpChannel * pSmtpCh, char const *pszServer,
			      char const *const *ppszAuthTokens, SMTPError * pSMTPE)
{

	if (StrStringsCount(ppszAuthTokens) < 3) {
		ErrSetErrorCode(ERR_BAD_SMTP_AUTH_CONFIG);
		return (ERR_BAD_SMTP_AUTH_CONFIG);
	}
///////////////////////////////////////////////////////////////////////////////
//  Send AUTH command
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse;
	char szAuthBuffer[1024] = "";

	sprintf(szAuthBuffer, "AUTH CRAM-MD5");

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 300) ||
	    (strlen(szAuthBuffer) < 4)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Retrieve server challenge
///////////////////////////////////////////////////////////////////////////////
	unsigned int uDec64Length = 0;
	char *pszAuth = szAuthBuffer + 4;
	char szChallenge[1024] = "";

	if (decode64(pszAuth, strlen(pszAuth), szChallenge, &uDec64Length) != 0) {
		if (pSMTPE != NULL)
			USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer, pSmtpCh->pszServer);

		ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		return (ERR_BAD_SERVER_RESPONSE);
	}
///////////////////////////////////////////////////////////////////////////////
//  Compute MD5 response ( secret , challenge , digest )
///////////////////////////////////////////////////////////////////////////////
	if (MscCramMD5(ppszAuthTokens[2], szChallenge, szChallenge) < 0)
		return (ErrGetErrorCode());

///////////////////////////////////////////////////////////////////////////////
//  Send response
///////////////////////////////////////////////////////////////////////////////
	unsigned int uEnc64Length = 0;
	char szResponse[1024] = "";

	SysSNPrintf(szResponse, sizeof(szResponse) - 1, "%s %s", ppszAuthTokens[1], szChallenge);

	encode64(szResponse, strlen(szResponse), szAuthBuffer,
		 sizeof(szAuthBuffer), &uEnc64Length);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}

	return (0);

}

static int USmtpExternalAuthSubstitute(char **ppszAuthTokens, char const *pszChallenge,
				       char const *pszSecret, char const *pszRespFile)
{

	for (int ii = 0; ppszAuthTokens[ii] != NULL; ii++) {
		if (strcmp(ppszAuthTokens[ii], "@@CHALL") == 0) {
			char *pszNewValue = SysStrDup(pszChallenge);

			if (pszNewValue == NULL)
				return (ErrGetErrorCode());

			SysFree(ppszAuthTokens[ii]);

			ppszAuthTokens[ii] = pszNewValue;
		} else if (strcmp(ppszAuthTokens[ii], "@@SECRT") == 0) {
			char *pszNewValue = SysStrDup(pszSecret);

			if (pszNewValue == NULL)
				return (ErrGetErrorCode());

			SysFree(ppszAuthTokens[ii]);

			ppszAuthTokens[ii] = pszNewValue;
		} else if (strcmp(ppszAuthTokens[ii], "@@RFILE") == 0) {
			char *pszNewValue = SysStrDup(pszRespFile);

			if (pszNewValue == NULL)
				return (ErrGetErrorCode());

			SysFree(ppszAuthTokens[ii]);

			ppszAuthTokens[ii] = pszNewValue;
		}
	}

	return (0);

}

static int USmtpDoExternAuth(SmtpChannel * pSmtpCh, char const *pszServer,
			     char **ppszAuthTokens, SMTPError * pSMTPE)
{

	if (StrStringsCount(ppszAuthTokens) < 4) {
		ErrSetErrorCode(ERR_BAD_SMTP_AUTH_CONFIG);
		return (ERR_BAD_SMTP_AUTH_CONFIG);
	}
///////////////////////////////////////////////////////////////////////////////
//  Send AUTH command
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse;
	char szAuthBuffer[1024] = "";

	SysSNPrintf(szAuthBuffer, sizeof(szAuthBuffer) - 1, "AUTH %s", ppszAuthTokens[1]);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 300)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Retrieve server challenge
///////////////////////////////////////////////////////////////////////////////
	unsigned int uDec64Length = 0;
	char *pszAuth = szAuthBuffer + 4;
	char szChallenge[1024] = "";

	if ((strlen(szAuthBuffer) < 4) ||
	    (decode64(pszAuth, strlen(pszAuth), szChallenge, &uDec64Length) != 0)) {
		if (pSMTPE != NULL)
			USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer, pSmtpCh->pszServer);

		ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		return (ERR_BAD_SERVER_RESPONSE);
	}
///////////////////////////////////////////////////////////////////////////////
//  Create temp filename for module response and do macro substitution
///////////////////////////////////////////////////////////////////////////////
	char szRespFile[SYS_MAX_PATH] = "";

	SysGetTmpFile(szRespFile);

	USmtpExternalAuthSubstitute(ppszAuthTokens, szChallenge, ppszAuthTokens[2], szRespFile);

///////////////////////////////////////////////////////////////////////////////
//  Call external program to compute the response
///////////////////////////////////////////////////////////////////////////////
	int iExitCode = -1;

	if (SysExec(ppszAuthTokens[3], &ppszAuthTokens[3], SMTP_EXTAUTH_TIMEOUT,
		    SMTP_EXTAUTH_PRIORITY, &iExitCode) < 0) {
		ErrorPush();
		CheckRemoveFile(szRespFile);

		return (ErrorPop());
	}

	if (iExitCode != SMTP_EXTAUTH_SUCCESS) {
		CheckRemoveFile(szRespFile);

		ErrSetErrorCode(ERR_BAD_EXTRNPRG_EXITCODE);
		return (ERR_BAD_EXTRNPRG_EXITCODE);
	}
///////////////////////////////////////////////////////////////////////////////
//  Load response file
///////////////////////////////////////////////////////////////////////////////
	unsigned int uRespSize = 0;
	char *pAuthResp = (char *) MscLoadFile(szRespFile, uRespSize);

	CheckRemoveFile(szRespFile);

	if (pAuthResp == NULL)
		return (ErrGetErrorCode());

	while ((uRespSize > 0) &&
	       ((pAuthResp[uRespSize - 1] == '\r') || (pAuthResp[uRespSize - 1] == '\n')))
		--uRespSize;

///////////////////////////////////////////////////////////////////////////////
//  Send response
///////////////////////////////////////////////////////////////////////////////
	unsigned int uEnc64Length = 0;

	encode64(pAuthResp, uRespSize, szAuthBuffer, sizeof(szAuthBuffer), &uEnc64Length);

	SysFree(pAuthResp);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szAuthBuffer,
							       szAuthBuffer,
							       sizeof(szAuthBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szAuthBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szAuthBuffer);
		}

		return (ErrGetErrorCode());
	}

	return (0);

}

static int USmtpServerAuthenticate(SmtpChannel * pSmtpCh, char const *pszServer,
				   SMTPError * pSMTPE)
{
///////////////////////////////////////////////////////////////////////////////
//  Try to retrieve SMTP authentication config for  "pszServer"
///////////////////////////////////////////////////////////////////////////////
	char szAuthFilePath[SYS_MAX_PATH] = "";

	if (USmtpGetServerAuthFile(pszServer, szAuthFilePath) < 0)
		return (0);

	FILE *pAuthFile = fopen(szAuthFilePath, "rt");

	if (pAuthFile == NULL) {
		ErrSetErrorCode(ERR_FILE_OPEN, szAuthFilePath);
		return (ERR_FILE_OPEN);
	}

	char szAuthLine[SMTPAUTH_LINE_MAX] = "";

	while (MscGetConfigLine(szAuthLine, sizeof(szAuthLine) - 1, pAuthFile) != NULL) {
		char **ppszTokens = StrGetTabLineStrings(szAuthLine);

		if (ppszTokens == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszTokens);

		if (iFieldsCount > 0) {
			int iAuthResult = 0;

			if (stricmp(ppszTokens[0], "plain") == 0)
				iAuthResult =
				    USmtpDoPlainAuth(pSmtpCh, pszServer, ppszTokens, pSMTPE);
			else if (stricmp(ppszTokens[0], "login") == 0)
				iAuthResult =
				    USmtpDoLoginAuth(pSmtpCh, pszServer, ppszTokens, pSMTPE);
			else if (stricmp(ppszTokens[0], "cram-md5") == 0)
				iAuthResult =
				    USmtpDoCramMD5Auth(pSmtpCh, pszServer, ppszTokens, pSMTPE);
			else if (stricmp(ppszTokens[0], "external") == 0)
				iAuthResult =
				    USmtpDoExternAuth(pSmtpCh, pszServer, ppszTokens, pSMTPE);
			else
				ErrSetErrorCode(iAuthResult =
						ERR_UNKNOWN_SMTP_AUTH, ppszTokens[0]);

			StrFreeStrings(ppszTokens);
			fclose(pAuthFile);

			return (iAuthResult);
		}

		StrFreeStrings(ppszTokens);
	}

	fclose(pAuthFile);

	return (0);

}

static int USmtpParseEhloResponse(SmtpChannel * pSmtpCh, char const *pszResponse)
{

	char const *pszLine = pszResponse;

	for (; pszLine != NULL; pszLine = strchr(pszLine, '\n')) {
		if (*pszLine == '\n')
			++pszLine;

///////////////////////////////////////////////////////////////////////////////
//  Skip SMTP code and ' ' or '-'
///////////////////////////////////////////////////////////////////////////////
		if (strlen(pszLine) < 4)
			continue;

		pszLine += 4;

///////////////////////////////////////////////////////////////////////////////
//  SIZE suport detection
///////////////////////////////////////////////////////////////////////////////
		if ((strnicmp(pszLine, "SIZE", CStringSize("SIZE")) == 0) &&
		    (strchr(" \r\n", pszLine[CStringSize("SIZE")]) != NULL)) {
			pSmtpCh->ulFlags |= SMTPCH_SUPPORT_SIZE;

			if ((pszLine[CStringSize("SIZE")] == ' ') &&
			    isdigit(pszLine[CStringSize("SIZE") + 1]))
				pSmtpCh->ulMaxMsgSize =
				    (unsigned long) atol(pszLine + CStringSize("SIZE") + 1);

			continue;
		}

	}

	return (0);

}

SMTPCH_HANDLE USmtpCreateChannel(const char *pszServer, const char *pszDomain, SMTPError * pSMTPE)
{
///////////////////////////////////////////////////////////////////////////////
//  Decode server address
///////////////////////////////////////////////////////////////////////////////
	int iPortNo = STD_SMTP_PORT;
	char szAddress[MAX_ADDR_NAME] = "";

	if (MscSplitAddressPort(pszServer, szAddress, iPortNo, STD_SMTP_PORT) < 0)
		return (INVALID_SMTPCH_HANDLE);

	SYS_INET_ADDR SvrAddr;

	if (MscGetServerAddress(szAddress, SvrAddr, iPortNo) < 0)
		return (INVALID_SMTPCH_HANDLE);

	SYS_SOCKET SockFD = SysCreateSocket(AF_INET, SOCK_STREAM, 0);

	if (SockFD == SYS_INVALID_SOCKET)
		return (INVALID_SMTPCH_HANDLE);

	if (SysConnect(SockFD, &SvrAddr, sizeof(SvrAddr), STD_SMTP_TIMEOUT) < 0) {
		SysCloseSocket(SockFD);
		return (INVALID_SMTPCH_HANDLE);
	}
///////////////////////////////////////////////////////////////////////////////
//  Check if We need to supply an HELO host
///////////////////////////////////////////////////////////////////////////////
	char szHeloHost[MAX_HOST_NAME] = "";

	if (pszDomain == NULL) {
///////////////////////////////////////////////////////////////////////////////
//  Get the DNS name of the local interface
///////////////////////////////////////////////////////////////////////////////
		if (MscGetSockHost(SockFD, szHeloHost) < 0) {
			SYS_INET_ADDR SockInfo;

			if (SysGetSockInfo(SockFD, SockInfo) < 0) {
				SysCloseSocket(SockFD);
				return (INVALID_SMTPCH_HANDLE);
			}

			char szIP[128] = "???.???.???.???";

			StrSNCpy(szHeloHost, SysInetNToA(SockInfo, szIP));
		}

		pszDomain = szHeloHost;
	}
///////////////////////////////////////////////////////////////////////////////
//  Attach socket to buffered reader
///////////////////////////////////////////////////////////////////////////////
	BSOCK_HANDLE hBSock = BSckAttach(SockFD);

	if (hBSock == INVALID_BSOCK_HANDLE) {
		SysCloseSocket(SockFD);
		return (INVALID_SMTPCH_HANDLE);
	}
///////////////////////////////////////////////////////////////////////////////
//  Read welcome message
///////////////////////////////////////////////////////////////////////////////
	SmtpChannel *pSmtpCh = (SmtpChannel *) SysAlloc(sizeof(SmtpChannel));

	if (pSmtpCh == NULL) {
		BSckDetach(hBSock, 1);
		return (INVALID_SMTPCH_HANDLE);
	}

	pSmtpCh->hBSock = hBSock;
	pSmtpCh->ulFlags = 0;
	pSmtpCh->ulMaxMsgSize = 0;
	pSmtpCh->SvrAddr = SvrAddr;
	pSmtpCh->pszServer = SysStrDup(pszServer);

///////////////////////////////////////////////////////////////////////////////
//  Read welcome message
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse = -1;
	char szRTXBuffer[2048] = "";

	if (!USmtpResponseClass(iSvrReponse = USmtpGetResponse(pSmtpCh->hBSock, szRTXBuffer,
							       sizeof(szRTXBuffer) - 1), 200)) {
		BSckDetach(pSmtpCh->hBSock, 1);

		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szRTXBuffer);
		}

		SysFree(pSmtpCh->pszServer);
		SysFree(pSmtpCh);

		return (INVALID_SMTPCH_HANDLE);
	}
///////////////////////////////////////////////////////////////////////////////
//  Try the EHLO ESMTP command before
///////////////////////////////////////////////////////////////////////////////
	SysSNPrintf(szRTXBuffer, sizeof(szRTXBuffer) - 1, "EHLO %s", pszDomain);

	if (USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szRTXBuffer,
							      szRTXBuffer,
							      sizeof(szRTXBuffer) - 1), 200)) {
///////////////////////////////////////////////////////////////////////////////
//  Parse EHLO response
///////////////////////////////////////////////////////////////////////////////
		if (USmtpParseEhloResponse(pSmtpCh, szRTXBuffer) < 0) {
			BSckDetach(pSmtpCh->hBSock, 1);
			SysFree(pSmtpCh->pszServer);
			SysFree(pSmtpCh);
			return (INVALID_SMTPCH_HANDLE);
		}

	} else {
///////////////////////////////////////////////////////////////////////////////
//  Send HELO and read result
///////////////////////////////////////////////////////////////////////////////
		SysSNPrintf(szRTXBuffer, sizeof(szRTXBuffer) - 1, "HELO %s", pszDomain);

		if (!USmtpResponseClass
		    (iSvrReponse =
		     USmtpSendCommand(pSmtpCh->hBSock, szRTXBuffer, szRTXBuffer,
				      sizeof(szRTXBuffer) - 1), 200)) {
			BSckDetach(pSmtpCh->hBSock, 1);

			if (iSvrReponse > 0) {
				if (pSMTPE != NULL)
					USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
						      pSmtpCh->pszServer);

				ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szRTXBuffer);
			}

			SysFree(pSmtpCh->pszServer);
			SysFree(pSmtpCh);

			return (INVALID_SMTPCH_HANDLE);
		}
	}

///////////////////////////////////////////////////////////////////////////////
//  Check if We need authentication
///////////////////////////////////////////////////////////////////////////////
	if (USmtpServerAuthenticate(pSmtpCh, szAddress, pSMTPE) < 0) {
		USmtpCloseChannel((SMTPCH_HANDLE) pSmtpCh, 0, pSMTPE);

		return (INVALID_SMTPCH_HANDLE);
	}

	return ((SMTPCH_HANDLE) pSmtpCh);

}

int USmtpCloseChannel(SMTPCH_HANDLE hSmtpCh, int iHardClose, SMTPError * pSMTPE)
{

	SmtpChannel *pSmtpCh = (SmtpChannel *) hSmtpCh;

	if (!iHardClose) {
///////////////////////////////////////////////////////////////////////////////
//  Send QUIT and read result
///////////////////////////////////////////////////////////////////////////////
		int iSvrReponse = -1;
		char szRTXBuffer[2048] = "";

		if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, "QUIT",
								       szRTXBuffer,
								       sizeof(szRTXBuffer) - 1),
					200)) {
			BSckDetach(pSmtpCh->hBSock, 1);

			if (iSvrReponse > 0) {
				if (pSMTPE != NULL)
					USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
						      pSmtpCh->pszServer);

				ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szRTXBuffer);
			}

			SysFree(pSmtpCh->pszServer);
			SysFree(pSmtpCh);

			return (ErrGetErrorCode());
		}
	}

	BSckDetach(pSmtpCh->hBSock, 1);

	SysFree(pSmtpCh->pszServer);

	SysFree(pSmtpCh);

	return (0);

}

int USmtpChannelReset(SMTPCH_HANDLE hSmtpCh, SMTPError * pSMTPE)
{

	SmtpChannel *pSmtpCh = (SmtpChannel *) hSmtpCh;

///////////////////////////////////////////////////////////////////////////////
//  Send RSET and read result
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse = -1;
	char szRTXBuffer[2048] = "";

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, "RSET",
							       szRTXBuffer,
							       sizeof(szRTXBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szRTXBuffer);
		}

		return (ErrGetErrorCode());
	}

	return (0);

}

int USmtpSendMail(SMTPCH_HANDLE hSmtpCh, const char *pszFrom, const char *pszRcpt,
		  FileSection const *pFS, SMTPError * pSMTPE)
{

	SmtpChannel *pSmtpCh = (SmtpChannel *) hSmtpCh;

///////////////////////////////////////////////////////////////////////////////
//  Check message size ( if the remote server support the SIZE extension )
///////////////////////////////////////////////////////////////////////////////
	unsigned long ulMessageSize = 0;

	if (pSmtpCh->ulMaxMsgSize != 0) {
		if (MscGetSectionSize(pFS, &ulMessageSize) < 0)
			return (ErrGetErrorCode());

		if (ulMessageSize >= pSmtpCh->ulMaxMsgSize) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, SMTP_FATAL_ERROR,
					      ErrGetErrorString(ERR_SMTPSRV_MSG_SIZE),
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_SMTPSRV_MSG_SIZE);
			return (ERR_SMTPSRV_MSG_SIZE);
		}
	}
///////////////////////////////////////////////////////////////////////////////
//  Send MAIL FROM: and read result
///////////////////////////////////////////////////////////////////////////////
	int iSvrReponse = -1;
	char szRTXBuffer[2048] = "";

	if (pSmtpCh->ulFlags & SMTPCH_SUPPORT_SIZE) {
		if ((ulMessageSize == 0) && (MscGetSectionSize(pFS, &ulMessageSize) < 0))
			return (ErrGetErrorCode());

		SysSNPrintf(szRTXBuffer, sizeof(szRTXBuffer) - 1, "MAIL FROM:<%s> SIZE=%lu",
			    pszFrom, ulMessageSize);
	} else
		SysSNPrintf(szRTXBuffer, sizeof(szRTXBuffer) - 1, "MAIL FROM:<%s>", pszFrom);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szRTXBuffer,
							       szRTXBuffer,
							       sizeof(szRTXBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_SMTP_BAD_MAIL_FROM, szRTXBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Send RCPT TO: and read result
///////////////////////////////////////////////////////////////////////////////
	SysSNPrintf(szRTXBuffer, sizeof(szRTXBuffer) - 1, "RCPT TO:<%s>", pszRcpt);

	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, szRTXBuffer,
							       szRTXBuffer,
							       sizeof(szRTXBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_SMTP_BAD_RCPT_TO, szRTXBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Send DATA and read the "ready to receive"
///////////////////////////////////////////////////////////////////////////////
	if (!USmtpResponseClass(iSvrReponse = USmtpSendCommand(pSmtpCh->hBSock, "DATA",
							       szRTXBuffer,
							       sizeof(szRTXBuffer) - 1), 300)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_SMTP_BAD_DATA, szRTXBuffer);
		}

		return (ErrGetErrorCode());
	}
///////////////////////////////////////////////////////////////////////////////
//  Send file
///////////////////////////////////////////////////////////////////////////////
	if (SysSendFile
	    (BSckGetAttachedSocket(pSmtpCh->hBSock), pFS->szFilePath, pFS->ulStartOffset,
	     pFS->ulEndOffset, STD_SMTP_TIMEOUT) < 0)
		return (ErrGetErrorCode());

///////////////////////////////////////////////////////////////////////////////
//  Send END OF DATA and read transfer result
///////////////////////////////////////////////////////////////////////////////
	if (BSckSendString(pSmtpCh->hBSock, ".", STD_SMTP_TIMEOUT) <= 0)
		return (ErrGetErrorCode());

	if (!USmtpResponseClass(iSvrReponse = USmtpGetResponse(pSmtpCh->hBSock, szRTXBuffer,
							       sizeof(szRTXBuffer) - 1), 200)) {
		if (iSvrReponse > 0) {
			if (pSMTPE != NULL)
				USmtpSetError(pSMTPE, iSvrReponse, szRTXBuffer,
					      pSmtpCh->pszServer);

			ErrSetErrorCode(ERR_BAD_SERVER_RESPONSE, szRTXBuffer);
		}

		return (ErrGetErrorCode());
	}

	return (0);

}

int USmtpSendMail(const char *pszServer, const char *pszDomain,
		  const char *pszFrom, const char *pszRcpt, FileSection const *pFS,
		  SMTPError * pSMTPE)
{
///////////////////////////////////////////////////////////////////////////////
//  Set server host name inside the SMTP error structure
///////////////////////////////////////////////////////////////////////////////
	if (pSMTPE != NULL)
		USmtpSetErrorServer(pSMTPE, pszServer);

///////////////////////////////////////////////////////////////////////////////
//  Open STMP channel and try to send the message
///////////////////////////////////////////////////////////////////////////////
	SMTPCH_HANDLE hSmtpCh = USmtpCreateChannel(pszServer, pszDomain, pSMTPE);

	if (hSmtpCh == INVALID_SMTPCH_HANDLE)
		return (ErrGetErrorCode());

	int iResultCode = USmtpSendMail(hSmtpCh, pszFrom, pszRcpt, pFS, pSMTPE);

	USmtpCloseChannel(hSmtpCh, 0, pSMTPE);

	return (iResultCode);

}

char *USmtpBuildRcptPath(char const *const *ppszRcptTo, SVRCFG_HANDLE hSvrConfig)
{

	int iRcptCount = StrStringsCount(ppszRcptTo);
	char szDestDomain[MAX_HOST_NAME] = "";

	if (USmtpSplitEmailAddr(ppszRcptTo[0], NULL, szDestDomain) < 0)
		return (NULL);

///////////////////////////////////////////////////////////////////////////////
//  Try to get routing path, if not found simply return an address concat
//  of "ppszRcptTo"
///////////////////////////////////////////////////////////////////////////////
	char szSpecMXHost[1024] = "";

	if (USmtpGetGateway(hSvrConfig, szDestDomain, szSpecMXHost) < 0)
		return (USmlAddrConcat(ppszRcptTo));

	char *pszSendRcpt = USmlAddrConcat(ppszRcptTo);

	if (pszSendRcpt == NULL)
		return (NULL);

	char *pszRcptPath = (char *) SysAlloc(strlen(pszSendRcpt) + strlen(szSpecMXHost) + 2);

	if (iRcptCount == 1)
		sprintf(pszRcptPath, "%s:%s", szSpecMXHost, pszSendRcpt);
	else
		sprintf(pszRcptPath, "%s,%s", szSpecMXHost, pszSendRcpt);

	SysFree(pszSendRcpt);

	return (pszRcptPath);

}

char **USmtpGetMailExchangers(SVRCFG_HANDLE hSvrConfig, const char *pszDomain)
{
///////////////////////////////////////////////////////////////////////////////
//  Try to get default gateways
///////////////////////////////////////////////////////////////////////////////
	char *pszDefaultGws = SvrGetConfigVar(hSvrConfig, "DefaultSMTPGateways");

	if (pszDefaultGws == NULL) {
		ErrSetErrorCode(ERR_NO_PREDEFINED_MX);
		return (NULL);
	}

	char **ppszMXGWs = StrTokenize(pszDefaultGws, ",; \t\r\n");

	SysFree(pszDefaultGws);

	return (ppszMXGWs);

}

static int USmtpGetDomainMX(SVRCFG_HANDLE hSvrConfig, const char *pszDomain, char *&pszMXDomains)
{
///////////////////////////////////////////////////////////////////////////////
//  Exist a configured list of smart DNS hosts ?
///////////////////////////////////////////////////////////////////////////////
	char *pszSmartDNS = SvrGetConfigVar(hSvrConfig, "SmartDNSHost");

	int iQueryResult = CDNS_GetDomainMX(pszDomain, pszMXDomains, pszSmartDNS);

	if (pszSmartDNS != NULL)
		SysFree(pszSmartDNS);

	return (iQueryResult);

}

int USmtpCheckMailDomain(SVRCFG_HANDLE hSvrConfig, char const *pszDomain)
{

	char *pszMXDomains = NULL;
	NET_ADDRESS NetAddr;

	if (USmtpGetDomainMX(hSvrConfig, pszDomain, pszMXDomains) < 0) {
		if (SysGetHostByName(pszDomain, NetAddr) < 0) {
			ErrSetErrorCode(ERR_INVALID_MAIL_DOMAIN);
			return (ERR_INVALID_MAIL_DOMAIN);
		}
	} else
		SysFree(pszMXDomains);

	return (0);

}

MXS_HANDLE USmtpGetMXFirst(SVRCFG_HANDLE hSvrConfig, const char *pszDomain, char *pszMXHost)
{

///////////////////////////////////////////////////////////////////////////////
//  Make a DNS query for domain MXs
///////////////////////////////////////////////////////////////////////////////
	char *pszMXHosts = NULL;

	if (USmtpGetDomainMX(hSvrConfig, pszDomain, pszMXHosts) < 0)
		return (INVALID_MXS_HANDLE);

///////////////////////////////////////////////////////////////////////////////
//  MX records structure allocation
///////////////////////////////////////////////////////////////////////////////
	SmtpMXRecords *pMXR = (SmtpMXRecords *) SysAlloc(sizeof(SmtpMXRecords));

	if (pMXR == NULL) {
		SysFree(pszMXHosts);
		return (INVALID_MXS_HANDLE);
	}

	pMXR->iNumMXRecords = 0;
	pMXR->iCurrMxCost = -1;

///////////////////////////////////////////////////////////////////////////////
//  MX hosts string format = c:h[,c:h]  where "c = cost" and "h = hosts"
///////////////////////////////////////////////////////////////////////////////
	int iMXCost = INT_MAX;
	int iCurrIndex = -1;
	char *pszToken = NULL;
	char *pszSavePtr = NULL;

	pszToken = SysStrTok(pszMXHosts, ":, \t\r\n", &pszSavePtr);

	while ((pMXR->iNumMXRecords < MAX_MX_RECORDS) && (pszToken != NULL)) {
///////////////////////////////////////////////////////////////////////////////
//  Get MX cost
///////////////////////////////////////////////////////////////////////////////
		int iCost = atoi(pszToken);

		if ((pszToken = SysStrTok(NULL, ":, \t\r\n", &pszSavePtr)) == NULL) {
			for (--pMXR->iNumMXRecords; pMXR->iNumMXRecords >= 0;
			     pMXR->iNumMXRecords--)
				SysFree(pMXR->pszMXName[pMXR->iNumMXRecords]);
			SysFree(pMXR);

			SysFree(pszMXHosts);

			ErrSetErrorCode(ERR_INVALID_MXRECS_STRING);
			return (INVALID_MXS_HANDLE);
		}

		pMXR->iMXCost[pMXR->iNumMXRecords] = iCost;
		pMXR->pszMXName[pMXR->iNumMXRecords] = SysStrDup(pszToken);

		if ((iCost < iMXCost) && (iCost >= pMXR->iCurrMxCost)) {
			iMXCost = iCost;

			strcpy(pszMXHost, pMXR->pszMXName[pMXR->iNumMXRecords]);

			iCurrIndex = pMXR->iNumMXRecords;
		}

		++pMXR->iNumMXRecords;

		pszToken = SysStrTok(NULL, ":, \t\r\n", &pszSavePtr);
	}

	SysFree(pszMXHosts);

	if (iMXCost == INT_MAX) {
		for (--pMXR->iNumMXRecords; pMXR->iNumMXRecords >= 0; pMXR->iNumMXRecords--)
			SysFree(pMXR->pszMXName[pMXR->iNumMXRecords]);
		SysFree(pMXR);

		ErrSetErrorCode(ERR_INVALID_MXRECS_STRING);
		return (INVALID_MXS_HANDLE);
	}

	pMXR->iCurrMxCost = iMXCost;
	pMXR->iMXCost[iCurrIndex] = iMXCost - 1;

	return ((MXS_HANDLE) pMXR);

}

int USmtpGetMXNext(MXS_HANDLE hMXSHandle, char *pszMXHost)
{

	SmtpMXRecords *pMXR = (SmtpMXRecords *) hMXSHandle;

	int iMXCost = INT_MAX;
	int iCurrIndex = -1;

	for (int ii = 0; ii < pMXR->iNumMXRecords; ii++) {
		if ((pMXR->iMXCost[ii] < iMXCost) && (pMXR->iMXCost[ii] >= pMXR->iCurrMxCost)) {
			iMXCost = pMXR->iMXCost[ii];

			strcpy(pszMXHost, pMXR->pszMXName[ii]);

			iCurrIndex = ii;
		}
	}

	if (iMXCost == INT_MAX) {
		ErrSetErrorCode(ERR_NO_MORE_MXRECORDS);
		return (ERR_NO_MORE_MXRECORDS);
	}

	pMXR->iCurrMxCost = iMXCost;
	pMXR->iMXCost[iCurrIndex] = iMXCost - 1;

	return (0);

}

void USmtpMXSClose(MXS_HANDLE hMXSHandle)
{

	SmtpMXRecords *pMXR = (SmtpMXRecords *) hMXSHandle;

	for (--pMXR->iNumMXRecords; pMXR->iNumMXRecords >= 0; pMXR->iNumMXRecords--)
		SysFree(pMXR->pszMXName[pMXR->iNumMXRecords]);

	SysFree(pMXR);

}

bool USmtpDnsMapsContained(SYS_INET_ADDR const &PeerInfo, char const *pszMapsServer)
{

	SYS_UINT8 AddrBytes[sizeof(NET_ADDRESS)];

	SysGetAddrAddress(PeerInfo, *((NET_ADDRESS *) AddrBytes));

	char szMapsQuery[256] = "";

	sprintf(szMapsQuery, "%u.%u.%u.%u.%s",
		(unsigned int) AddrBytes[3], (unsigned int) AddrBytes[2],
		(unsigned int) AddrBytes[1], (unsigned int) AddrBytes[0], pszMapsServer);

	NET_ADDRESS NetAddr;

	return ((SysGetHostByName(szMapsQuery, NetAddr) < 0) ? false : true);

}

static char *USmtpGetSpammersFilePath(char *pszSpamFilePath, int iMaxPath)
{

	CfgGetRootPath(pszSpamFilePath, iMaxPath);

	StrNCat(pszSpamFilePath, SMTP_SPAMMERS_FILE, iMaxPath);

	return (pszSpamFilePath);

}

int USmtpSpammerCheck(const SYS_INET_ADDR & PeerInfo, char *&pszInfo)
{

	pszInfo = NULL;

	char szSpammersFilePath[SYS_MAX_PATH] = "";

	USmtpGetSpammersFilePath(szSpammersFilePath, sizeof(szSpammersFilePath));

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockSH(CfgGetBasedPath(szSpammersFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (ErrGetErrorCode());

	FILE *pSpammersFile = fopen(szSpammersFilePath, "rt");

	if (pSpammersFile == NULL) {
		RLckUnlockSH(hResLock);

		ErrSetErrorCode(ERR_FILE_OPEN);
		return (ERR_FILE_OPEN);
	}

	NET_ADDRESS TestAddr;

	SysGetAddrAddress(PeerInfo, TestAddr);

	char szSpammerLine[SPAMMERS_LINE_MAX] = "";

	while (MscGetConfigLine(szSpammerLine, sizeof(szSpammerLine) - 1, pSpammersFile) != NULL) {
		char **ppszStrings = StrGetTabLineStrings(szSpammerLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);

		if (iFieldsCount < 1) {
			StrFreeStrings(ppszStrings);
			continue;
		}

		int iAddrFields = 1;

		if ((iFieldsCount > 1) && isdigit(ppszStrings[1][0]))
			iAddrFields = 2;

		AddressFilter AF;

		if ((MscLoadAddressFilter(ppszStrings, iAddrFields, AF) == 0) &&
		    MscAddressMatch(AF, TestAddr)) {
			if (iFieldsCount > iAddrFields)
				pszInfo = SysStrDup(ppszStrings[iAddrFields]);

			StrFreeStrings(ppszStrings);
			fclose(pSpammersFile);
			RLckUnlockSH(hResLock);

			char szIP[128] = "???.???.???.???";

			ErrSetErrorCode(ERR_SPAMMER_IP, SysInetNToA(PeerInfo, szIP));
			return (ERR_SPAMMER_IP);
		}

		StrFreeStrings(ppszStrings);
	}

	fclose(pSpammersFile);

	RLckUnlockSH(hResLock);

	return (0);

}

static char *USmtpGetSpamAddrFilePath(char *pszSpamFilePath, int iMaxPath)
{

	CfgGetRootPath(pszSpamFilePath, iMaxPath);

	StrNCat(pszSpamFilePath, SMTP_SPAM_ADDRESS_FILE, iMaxPath);

	return (pszSpamFilePath);

}

int USmtpSpamAddressCheck(char const *pszAddress)
{

	char szSpammersFilePath[SYS_MAX_PATH] = "";

	USmtpGetSpamAddrFilePath(szSpammersFilePath, sizeof(szSpammersFilePath));

	char szResLock[SYS_MAX_PATH] = "";
	RLCK_HANDLE hResLock = RLckLockSH(CfgGetBasedPath(szSpammersFilePath, szResLock,
							  sizeof(szResLock)));

	if (hResLock == INVALID_RLCK_HANDLE)
		return (ErrGetErrorCode());

	FILE *pSpammersFile = fopen(szSpammersFilePath, "rt");

	if (pSpammersFile == NULL) {
		RLckUnlockSH(hResLock);
		return (0);
	}

	char szSpammerLine[SPAM_ADDRESS_LINE_MAX] = "";

	while (MscGetConfigLine(szSpammerLine, sizeof(szSpammerLine) - 1, pSpammersFile) != NULL) {
		char **ppszStrings = StrGetTabLineStrings(szSpammerLine);

		if (ppszStrings == NULL)
			continue;

		int iFieldsCount = StrStringsCount(ppszStrings);

		if ((iFieldsCount > 0) && StrIWildMatch(pszAddress, ppszStrings[0])) {
			StrFreeStrings(ppszStrings);
			fclose(pSpammersFile);
			RLckUnlockSH(hResLock);

			ErrSetErrorCode(ERR_SPAM_ADDRESS, pszAddress);
			return (ERR_SPAM_ADDRESS);
		}

		StrFreeStrings(ppszStrings);
	}

	fclose(pSpammersFile);

	RLckUnlockSH(hResLock);

	return (0);

}

int USmtpAddMessageInfo(FILE * pMsgFile, char const *pszClientDomain,
			SYS_INET_ADDR const &PeerInfo, char const *pszServerDomain,
			SYS_INET_ADDR const &SockInfo, char const *pszSmtpServerLogo)
{

	char szTime[256] = "";

	MscGetTimeStr(szTime, sizeof(szTime) - 1);

	char szPeerIP[128] = "";
	char szSockIP[128] = "";

	SysInetNToA(PeerInfo, szPeerIP);
	SysInetNToA(SockInfo, szSockIP);

///////////////////////////////////////////////////////////////////////////////
//  Write message info. If You change the order ( or add new fields ) You must
//  arrange fields into the SmtpMsgInfo union defined in SMTPUtils.h
///////////////////////////////////////////////////////////////////////////////
	fprintf(pMsgFile, "%s;%s:%d;%s;%s:%d;%s;%s\r\n",
		pszClientDomain, szPeerIP, SysGetAddrPort(PeerInfo),
		pszServerDomain, szSockIP, SysGetAddrPort(SockInfo), szTime, pszSmtpServerLogo);

	return (0);

}

int USmtpWriteInfoLine(FILE * pSpoolFile, char const *pszClientAddr,
		       char const *pszServerAddr, char const *pszTime)
{

	fprintf(pSpoolFile, "%s;%s;%s\r\n", pszClientAddr, pszServerAddr, pszTime);

	return (0);

}

char *USmtpGetReceived(int iType, char const *pszAuth, char const *const *ppszMsgInfo,
		       char const *pszMailFrom, char const *pszRcptTo, char const *pszMessageID)
{

	char szFrom[MAX_SMTP_ADDRESS] = "";
	char szRcpt[MAX_SMTP_ADDRESS] = "";

	if ((USmlParseAddress(pszMailFrom, NULL, 0, szFrom, sizeof(szFrom) - 1) < 0) ||
	    (USmlParseAddress(pszRcptTo, NULL, 0, szRcpt, sizeof(szRcpt) - 1) < 0))
		return (NULL);

///////////////////////////////////////////////////////////////////////////////
//  Parse special types to hide client info
///////////////////////////////////////////////////////////////////////////////
	bool bHideClient = false;

	if (iType == RECEIVED_TYPE_AUTHSTD) {
		bHideClient = (pszAuth != NULL) && !IsEmptyString(pszAuth);
		iType = RECEIVED_TYPE_STD;
	} else if (iType == RECEIVED_TYPE_AUTHVERBOSE) {
		bHideClient = (pszAuth != NULL) && !IsEmptyString(pszAuth);
		iType = RECEIVED_TYPE_VERBOSE;
	}
///////////////////////////////////////////////////////////////////////////////
//  Return "Received:" tag
///////////////////////////////////////////////////////////////////////////////
	char *pszReceived = NULL;

	switch (iType) {
	case (RECEIVED_TYPE_STRICT):
		pszReceived = StrSprint("Received: from %s\r\n"
					"\tby %s with %s\r\n"
					"\tid <%s> for <%s> from <%s>;\r\n"
					"\t%s\r\n", ppszMsgInfo[smsgiClientDomain],
					ppszMsgInfo[smsgiServerDomain],
					ppszMsgInfo[smsgiSeverName], pszMessageID, szRcpt, szFrom,
					ppszMsgInfo[smsgiTime]);
		break;

	case (RECEIVED_TYPE_VERBOSE):
		if (!bHideClient)
			pszReceived = StrSprint("Received: from %s (%s)\r\n"
						"\tby %s (%s) with %s\r\n"
						"\tid <%s> for <%s> from <%s>;\r\n"
						"\t%s\r\n", ppszMsgInfo[smsgiClientDomain],
						ppszMsgInfo[smsgiClientAddr],
						ppszMsgInfo[smsgiServerDomain],
						ppszMsgInfo[smsgiServerAddr],
						ppszMsgInfo[smsgiSeverName], pszMessageID, szRcpt,
						szFrom, ppszMsgInfo[smsgiTime]);
		else
			pszReceived = StrSprint("Received: from %s\r\n"
						"\tby %s (%s) with %s\r\n"
						"\tid <%s> for <%s> from <%s>;\r\n"
						"\t%s\r\n", ppszMsgInfo[smsgiClientDomain],
						ppszMsgInfo[smsgiServerDomain],
						ppszMsgInfo[smsgiServerAddr],
						ppszMsgInfo[smsgiSeverName], pszMessageID, szRcpt,
						szFrom, ppszMsgInfo[smsgiTime]);
		break;

	case (RECEIVED_TYPE_STD):
	default:
		if (!bHideClient)
			pszReceived = StrSprint("Received: from %s (%s)\r\n"
						"\tby %s with %s\r\n"
						"\tid <%s> for <%s> from <%s>;\r\n"
						"\t%s\r\n", ppszMsgInfo[smsgiClientDomain],
						ppszMsgInfo[smsgiClientAddr],
						ppszMsgInfo[smsgiServerDomain],
						ppszMsgInfo[smsgiSeverName], pszMessageID, szRcpt,
						szFrom, ppszMsgInfo[smsgiTime]);
		else
			pszReceived = StrSprint("Received: from %s\r\n"
						"\tby %s with %s\r\n"
						"\tid <%s> for <%s> from <%s>;\r\n"
						"\t%s\r\n", ppszMsgInfo[smsgiClientDomain],
						ppszMsgInfo[smsgiServerDomain],
						ppszMsgInfo[smsgiSeverName], pszMessageID, szRcpt,
						szFrom, ppszMsgInfo[smsgiTime]);
		break;
	}

	return (pszReceived);

}