Let's say I sort all my mail from a mailing list to one folder, and all my mail from friends to another. If I get a message from my friend sent to both me and the folder, I would like for it to show up in both folders.
I believe this is the main idea behind "search folders." All your mail is actually just in one place (one mailbox) but you can have multiple views over this (and preferrably the views are arranged hierarchically, instead of a flat list, so I could have the views 'Friends' and 'Friends/Joe'). In other words, they're like instant search filters.
I realize that this is probably implemented in clients (just a matter of building/maintaining an index over the mail), but with multiple clients, you'd have to reproduce and synchronize the filters for each of them, and also the server wouldn't be filtering these for you as the mail comes in.
What I was mentioning were the attributes which I read about in the IMAP RFC. These were intended for things like 'Seen', 'Answered', 'Flagged', etc. What I'm wonder is if it's possible, efficient, or even a convention to use them for views ('Some mailing list', 'Friends/Joe', 'Sent directly to me', etc,). Or perhaps there is a better way? Or no way at all?
(4) (This is more of an IMAP protocol question.) I glanced at the RFC for IMAP. Is there the concept of views/search folders/dynamic filters? It seems that the 'mailbox' concept is like a folder, in that a message can only belong to one. The closest thing I could find was the attribute, but it was intended for things like 'read', etc.; can this be used for the above purpose, or is IMAP not a good protocol to use for searching?
I don't understand this question. Please rephrase it, and avoid the use of the word "folder" which has imprecise meaning. Use the term "mailbox" (a name that holds messages), "directory" (a name that holds other names), or "dual-use name" (a name that is both a mailbox and a directory).
