Here's when you shouldn't use post office drop boxes, according to

Lock the parcel compartment and drop the parcel key in the outgoing mail slot of the community mailbox Where are larger parcels delivered? We'll deliver

If you're returning an item or buying postage online with Click & Drop or the Royal Mail App, you can now drop them off at a Parcel Postbox near you Parcel

mailbox slot cover If you're returning an item or buying postage online with Click & Drop or the Royal Mail App, you can now drop them off at a Parcel Postbox near you Parcel

mailbox drop slot Install this modern mail slot in an external wall and secure incoming mail or packages with the patented Security Drop Door The Package Drop Vault Plus