#define SMTP_PORT 25 //порт почтового сервера
#define SMTP_ADDR "128.1.1.1" //Айпишник почтового сервера

int rc;
WSADATA WSAData;

rc = WSAStartup(MAKEWORD(1, 1), &WSAData);
if(rc != 0) return FALSE;

SOCKET nSMTPServerSocket;
struct sockaddr_in smtp_address;
int nConnect;
int iLength;
int iMsg = 0;
int iEnd = 0;
BYTE sBuf[4096];

char *MailMessage[] =
{
"HELO domain.ru\r\n",
"MAIL FROM:<",
"RCPT TO:\r\n",
"DATA\r\n",
"",
"QUIT\r\n",
NULL
};

lstrcat(MailMessage[1], "purpe@sources.ru>\r\n");
lstrcat(MailMessage[4],"Hello world\r\n\r\n.\r\n");

nSMTPServerSocket = socket(PF_INET, SOCK_STREAM, 0);

if(nSMTPServerSocket != INVALID_SOCKET) {
smtp_address.sin_family = AF_INET;
smtp_address.sin_addr.s_addr = inet_addr(SMTP_ADDR);
smtp_address.sin_port = htons(SMTP_PORT);

nConnect = connect(nSMTPServerSocket, (PSOCKADDR)&smtp_address,
sizeof(smtp_address));

if(nConnect) { }
else {
do {
iLength = recv(nSMTPServerSocket, (LPSTR)sBuf+iEnd, sizeof(sBuf)-iEnd, 0);
iEnd += iLength;
sBuf[iEnd] = '\0';
send(nSMTPServerSocket, (LPSTR)MailMessage[iMsg], strlen(MailMessage[iMsg]),
0);
iMsg++;
} while(MailMessage[iMsg]);
}

closesocket(nSMTPServerSocket);
}