My GTD system has a weak point when it comes to digital project support material. I receive lots of files (.xls, .doc, .ppt, .pdf etc. etc.) through e-mail. I need these files to be searchable via Spotlight, so I have to save them on the hard disk. The problem arises when - and this is often - I need to keep the enclosing e-mail together with the enclosed file(s). How should I 'tie' the e-mail to the files on the hard disk? The only fool-proof solution that I've found is to create a dedicated folder for the e-mail and all its contents, but as you can imagine, that is not at all practical when receiving lots of mail. Any ideas/suggestions?