Saving email attachment in (sub)directories

When I receive attached files to emails while using Thunderbird email service, I want to save them in Directories or Subdirectories on either my mobile hard disk or USB stick(s). But it seems not possible to do that directly. I always have to save attachments in the root directories of the storing media, and then go and organize these files with "Finder".

I guess I have to attach a question to above statement. I would really like some help with saving attachments in (sub)directories. There must be a solution for it!!!