One of the recommendations in a fire risk assessment report commissioned by us was that fire-resistant mailboxes should be installed in the ground floor entrance lobby. The wooden frame in which letters and small parcels were being stored were deemed to be a fire hazard as these were readily combustible and would have served as a source of fuel to a fire affecting the common areas.
We have now installed fire rated mailboxes that include a number of specially designed features to meet fire rating standards BS EN 1363-1: 2012. These mailboxes use a fire cover which limits the access to the mailbox lock and the mailbox flap uses an inward sprung hinge to stop the flap from falling out of the box. The mailbox aperture uses an intumescent seal which expands when exposed to a large increase in temperature; closing the gap and restricting the flow of oxygen into the mailbox.
Each flat has its own mailbox with a set of keys. The keys to the mailbox should be treated in the same manner as the keys to your flat and you will be solely responsible for replacing them. Click lost keys, etc for useful information regarding the keys.