folders tree

Hello
I would appreciate some advice on sorting my emails as I seem to have got in a muddle.
I have only one account/email address and I did import emails several years ago from another email client - However my folder tree on the left pane looks like this - hoping for a suggestion on how to tidy it up - unread reads 2067 but I really have read them or deleted them

Smart folders
   All inboxes   487
   Unread   2067
   Flagged   333

then my email address

   inbox   487
   outbox
   sent   128
   trash   1631
   drafts   21
   junk email
   
Local inbox

  inbox
  outbox
   sent
   trash
   drafts
   junk
   notes