my suggestion is simple.
We need a "Uncollected" tab on mailbox because we're wasting so much time looking for a uncollected mail in all those pages.
The Unread tab doesn't help because, sometimes we try to collect someting and our bag is full, and that mail change from unread to read. This is so annoying, and im sure everyone who plays this game thinks the same.
The deleting pages process is boring and slow, we have to go to every page repeting "mark all > delete all", last time i had 90+ pages...
Please consider my suggestion, thanks!