Dovecot: is it possible to issue letters via imap for a limited period of time?

Question

IMAP

The problem is this:
Users have long-term mailboxes, the volume of which for many has exceeded 10k letters. Quotas cannot be used due to company policy. Auto-delete of old letters - even more so. With one attempt to hint, why do you need letters from 5 years ago - almost a hysteria and one answer - What if you need it?
The consequence of this are periodic server brakes. Especially when the general opens an email client (the counter of his letters has exceeded 700k)
And actually, I would like to limit the output of the list of letters by imap by the statute of limitations. Let's say that letters were issued only for the last year and a half. And the rest - on request (say, called - asked for access to the archive - got access before the end of the day).
The option with the virtual plugin is not suitable, due to the fact that everyone has a sorter and folders configured, and virtual, as far as I know, will display a list without folders nested in INBOX.
The restriction on the client side also does not fit - everyone is free to connect their box anywhere, even on a mobile phone you simply cannot keep up with everyone.
So far, only one option has matured - once a day to run through the boxes and letters, transfer the archive to a folder older than a year. Crutch, but in principle it will work. But what if there is a solution using dovecot itself?
Bundle: Debian-exim-dovecot+authorization via ad