static const char *payload_text[] = {
  ,
   to ,
   from ,
   cc ,
  
  ,
  ,
  ,
  ,
  ,
  ,
  ,
  ,
  ,
  NULL
};

struct upload_status {
  int lines_read;
};

static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp)
{
  struct upload_status *upload_ctx = (struct upload_status *)userp;
  const char *data;

  if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
    return 0;
  }

  data = payload_text[upload_ctx->lines_read];

  if(data) {
    size_t len = strlen(data);
    memcpy(ptr, data, len);
    upload_ctx->lines_read++;

    return len;
  }

  return 0;
}

int main(void)
{
  CURL *curl;
  CURLcode res = CURLE_OK;
  struct curl_slist *recipients = NULL;
  struct upload_status upload_ctx;

  upload_ctx.lines_read = 0;

  curl = curl_easy_init();
  if(curl) {

    curl_easy_setopt(curl, CURLOPT_USERNAME, );
    curl_easy_setopt(curl, CURLOPT_PASSWORD, );

    curl_easy_setopt(curl, CURLOPT_URL, );

    curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL);

    curl_easy_setopt(curl, CURLOPT_CAINFO, );

    curl_easy_setopt(curl, CURLOPT_MAIL_FROM, from);

    recipients = curl_slist_append(recipients, to);
    recipients = curl_slist_append(recipients, cc);
    curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);

    curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
    curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
    curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);

    res = curl_easy_perform(curl);

    if(res != CURLE_OK)
      fprintf(stderr, ,curl_easy_strerror(res));

    curl_slist_free_all(recipients);

    curl_easy_cleanup(curl);
  }

  return (int)res;
}