Filesnames with FUSE and IMAP

I want to build a fuse-filesystem with IMAP4 in python. As filename I would like to use the subject of each mail. So I can rename the filenames and with this the Subjects.

But subjects can be used several times in one directory, so this breaks the com开发者_运维百科mon filesystem rules.

I wouldn't like to use a difficult directory-system (like here) nor the unique Message-ID (then I cannot rename my files and directories).

I want to use e-mails in imap as (fuse-)directories and attachments of these mails as (fuse-)files. (For that only one layer of directories is possible.) The intention of this imapfs is to use mails as a storage-possibility.

Are there any suggestions how to deal with this filename problem? Thanks for any incitements.