private void AddBlobToMultipartContent(MultipartContent content, Blob blob)
{
HttpContent part = new StreamContent(blob.File.OpenRead());
part.Headers.ContentType = new MediaTypeHeaderValue(blob.MimeType);
part.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
FileName = blob.Filename
};
part.Headers.Add("Content-Transfer-Encoding", "binary");
part.Headers.Add("Content-ID", "input");
content.Add(part);
}