Considering the only way to delete very old emails is one at a time per page AND there's no way fir many of us to see our current usage AND you intend to cut off access to those using too much space...

Provide a better way to delete old mail. Don't require emptying folders to delete them. Perhaps allow a mass delete of anything older than an entered date. Put in a "go to oldest page" option in the inbox and folders.

Provide the info you claim is in the settings so I CAN figure out how much space I'm using.