Hi Tim! I know I can use "storage", but that's for a different purpose...
The "recover deleted messages" option and function in MS Exchange and in Kerio Connect are designed to give the end user (the single user of the single mailbox... You don't need to be an administrator) to have the possibility to recover PERMANENTLY deleted emails (even those deleted from Outlook using the SHIFT+DEL key combination) by mistake within a certain number of days (usually 30, but can be configurable).
After 30 days the emails are no longer recoverable and are also deleted from the server.
Besides that, this feature is directly supported within Outlook, so you don't need to access the server via webmail.
The archive, on the other hand, is a different thing...
That said, mine is just a proposal for a new feature that seems useful to me (having seen and used it for years in other systems), but I'll understand you (albeit with some regret) if the final decision is not to implement it.