I'm often on a slow connection, and having Davmail reload the full list of messages from the server every time I click on a folder in my IMAP client can really be exhausting.
Perhaps it is due to Thunderbird issuing a SELECT when some lighter-weight commands could suffice, but I don't see any possibility to change that behavior on the TB side.
Using a caching mechanism on the Davmail side could speed thing up quite significantly: what I imagine is that Davmail would load the full message list for the first SELECT command in the session, and then cache the result for all subsequent SELECTs, until some reason to refresh comes around, or at least for the set IDLE time, unless there's an explicit command to fetch all messages again, such as CHECK.
Thanks
Mauro
Unfortunately caching would probably fail in some cases, e.g. on concurrent folder access.
Anyway you can try to use the folderSizeLimit setting to get only recent messages.