As we know, few months ago Gmail lunched Gmail Lab features. This features mainly using to experimenting new features to sharing with gmail users with most convenient way.
Most recently gmail’s official blog published about Gmail IMAP (Internet Message Access Protocol) accessing features. Which enabling more control and now it’s available in Gmail Lab. Whenever, you enable this features thus you will get more control. Gmail blog said,
“if you find your mail client choking on a big All Mail folder,” – then you can select your desired folder.
Gmail’s blog said, “The IMAP protocol allows messages to be marked for deletion, a sort of
limbo state where a message is still present in the folder but slated to be deleted the next time the folder is expunged. In our standard IMAP implementation, when you mark a message as deleted, Gmail doesn’t let it linger in that state — it deletes (or auto-expunges) it from the folder right away. If you want the two-stage delete process, after you’ve enabled this Lab, just select ‘Do not automatically expunge messages’ under the ‘Forwarding and POP/IMAP’ tab in Settings.”
You can read more details at GoogleSystem.