Thunderbird:Replace Normal Folders with Virtual Folders
When using Virtual Folders, Thunderbird will save all messages into a single database. Each message will have a set of metadata associated with it, such as From, To, Account, Junk Status etc. The folder hierachy will be constructed from these metadata.
A new metadata field, keywords, will be provided for the user to add customized labels/tags to each message. They can add keywords by typing them in, through filters or by dragging them to a folder. Each normal folder will be associated with 1 or more keywords, but not other metadata (however, special folders, such as the junk folder, can associated with any metadata, including keywords). This basically means a particular message can appear under several folders.
I believe this system is far more flexible than the current system and it works better with database, which will be used as the storage backend for Mozilla 2.0
- I'm not sure whether it's ever been clarified that we'll be switching from mbox-based mail storage to SQLite-based storage. If indeed we are, it might be worth considering adding a mail export feature at the same time so that prospective users will feel more comfortable testing out Thunderbird without having to lose some of their mail (because it's in a mail system which isn't importable existing mail clients.
- Along the same lines, it's worth considering how mail will be exported when it doesn't truly have one parent folder. If there are multiple parent folders (categories, labels, what-have-you), which one will store the mail when it gets exported? (This assumes export happens at the same time as this feature's added, per above -- if it doesn't, it's still a consideration for when export is added.)--Waldo