smtp mime 附件+文本编码发送

调了两天，终于调通。
回车换行都会有影响，可以用foxmail，查看邮件源码来调试。

    fprintf(pFile, "From:%s\n",smtp.szSender);
    fprintf(pFile, "To:%s\n",smtp.szRecver);
    fprintf(pFile, "Subject:%s\n",smtp.szTitle);
    fprintf(pFile, "MIME-Version: 1.0\n");
    fprintf(pFile, "Content-Type:multipart/mixed;\n");                        //添加附件必须！可以看下MIME协议
    fprintf(pFile, " boundary=\"=====001_NextPart167448323667_=====\"\n");    //邮件正文开始

    fprintf(pFile, "\r\n");
    fprintf(pFile, "--=====001_NextPart167448323667_=====\n");                 //段开始标识
    fprintf(pFile, "Content-Type:multipart/alternative;\n");                   //文本和超文本，添加此标识
    fprintf(pFile, " boundary=\"=====002_NextPart167448323667_=====\"\r\n");   //boundary 有开始也要有结束

    fprintf(pFile, "--=====002_NextPart167448323667_=====\n");
    fprintf(pFile, "Content-Type: text/plain; charset=\"UTF-8\"\n");
    fprintf(pFile, "Content-Transfer-Encoding: base64\r\n");

    sprintf(buf_str,"Hello!\n    This e-mail is come from montion detection of IPNC.\n");

    base64Encode(buf_str,buf_out,strlen(buf_str) + 1,&len_out);
    fprintf(pFile, "%s\r\n",buf_out);
    fprintf(pFile, "--=====002_NextPart167448323667_=====--\r\n");


    fprintf(pFile, "--=====001_NextPart167448323667_=====\n");
    fprintf(pFile, "Content-Transfer-Encoding: base64\n");
    fprintf(pFile, "Content-Type:image/jpeg; name=\"%s\"\n",pt);
    fprintf(pFile, "Content-Disposition: attachment; filename=%s\r\n\r\n",pt);

    base64Encode_file(in, pFile, ufile_size);


    fprintf(pFile, "\n--=====001_NextPart167448323667_=====--\r\n\r\n");    // 邮件结束