Comment 156 for bug 275471

(In reply to comment #147)
> The disk and memory cache complicate this quite a bit. Also, simply clicking
> on a message with a large external attachment should not end up with it
> getting put in the offline store. You'd need the imap auto sync to do that,
> or the aforementioned download now button.

I would love a simple way to completely and utterly disable disk/memory caching, and use only offline storage.