使用smtp发送邮件(源码)

    源文件：

    #include <vcl.h>
    #pragma hdrstop

    #include "sendmail.h"
    #include "mmsystem.h"

    #pragma package(smart_init)

    struct RecvEmailInfo
    {
        AnsiString     strSubject, strFrom, strTo, strContent, strCmdDate, strCmdNum;
        int            nRecNum, nSendCount;
        TList         *AttachList;
    };

    struct AttachInfo
    {
        AnsiString     FileName;
        int            Length;
        BYTE          *Content;
    };
    __fastcall TSendMailThread::TSendMailThread(bool CreateSuspended,int sleeptime )
     : TThread(CreateSuspended)
    {
     Ftime           = sleeptime;
        FreeOnTerminate = true;
        nSendFlag       = -1;
        nCommandKind    = 0;
        strBoundary     = "----Mailor_of_qurqur.China----";

        RecvEmailList= new TList;

        /*TMemoryStream *ms = new TMemoryStream();
        ms->LoadFromFile( "d:\\test.txt" );
        RecvEmailInfo * pREI;
        AttachInfo * pAI;
        for( int i = 0; i < 5; i ++ )
        {
            pAI = new AttachInfo;
            pREI = new RecvEmailInfo;
            pAI->FileName = "test.txt";
            pAI->Length   = ms->Size;
            pAI->Content = new BYTE[ ms->Size ];
            ms->Position = 0;
            ms->ReadBuffer( pAI->Content, ms->Size );
            pREI->AttachList = new TList;
            pREI->AttachList->Add( pAI );
            pREI->strSubject = "humor";
            pREI->strFrom = "[email protected]";
            pREI->strTo   = "[email protected];
            pREI->strContent = "test";
            pREI->nSendCount = 5;
            RecvEmailList->Add( pREI );
        }
        delete ms;*/
    }
    void __fastcall TSendMailThread::Execute()
    {
        WORD wVersionRequested;
        WSADATA wsaData;
        int err;

        wVersionRequested = MAKEWORD( 2, 2 );

        err = WSAStartup( wVersionRequested, &wsaData );
        if ( err != 0 )
        {
            // Tell the user that we could not find a usable WinSock DLL.
            return;
        }
        if ( LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 )
        {
            // Tell the user that we could not find a usable WinSock DLL.
            WSACleanup( );
            return;
        }

     while( !Terminated )
        {
            if( !bCanSendEmail )
            {
                Sleep( Ftime );
                continue;
            }
            SendDeal();
            Sleep( 10 );
        }
    }
    int __fastcall TSendMailThread::InitSocket()
    {
        smtpclient = socket( AF_INET, SOCK_STREAM, 0 );
        if( smtpclient == INVALID_SOCKET )
        {
            return -1;
        }
        HOSTENT* hostinfo = gethostbyname( strSMTPServer.c_str() );
        if( hostinfo == NULL )
            return -1;

        struct sockaddr_in server;
        server.sin_family = AF_INET;
        server.sin_port = htons( nSMTPPort );
        memcpy( &server.sin_addr, *hostinfo->h_addr_list, sizeof( server.sin_addr ) );
        int rval = connect( smtpclient, ( struct sockaddr* )&server, sizeof( server ) );
        if( rval == SOCKET_ERROR )
        {
           // rval = WSAGetLastError();
            return -1;
        }
        return 0;
    }
    void __fastcall TSendMailThread::SendDeal()
    {
        unsigned int new_time;
        char aa[ 8200 ];
        int err, len;
        switch( nSendFlag )
        {
        case -1 :
           if( HaveEmail() )
           {
               err = InitSocket();
               if( err == -1 )
               {
                   nSendFlag = 1;

                  strcpy( buf, "error" );

                  nCommandKind = 9;

               }