If your mailboxes are using those GEM or standard camlock keys then the problem will persist.
You need to use the appropriate camlocks.
Regarding common areas access the use of electronic credentials can help but once again only if using the right system, thus no any HID products, they just emailed all distributors about their latest SEOS system that is now cracked like everything else they manufacture…
Using virtual card on mobile phone is currently the most secured way to secure a building and to stop wasting time and money managing and buying physical credentials.