Inbound and outward bound mail is normally necessary to be maintained in a safe and sound location and that will mean limiting access to the mail.
There are numerous options with professional mailboxes which provide the security needed, and most are permitted to be used by the United States Postal Service.
The biggest thing with commercial security locking mailboxes, even those in which services are used by government office buildings is the letter carrier will need to have easy accessibility to all of the separate boxes without the need to open each and every one.
Typically, commercial letterboxes will have one entry point for the letter carrier, generally at the back of the mailbox, into which the postal mail might be delivered into individual boxes.
As soon as the rear door is open, the letter carrier has access to all the letter boxes whilst in the front each and every separate box is secured with a key lock preventing unauthorized access into the other containers.
Some locking commercial mail boxes are secured onto a wall with no rear access and for these the entire front of the mailbox can be opened up allowing the mail to be delivered into the separate letter boxes. When the front section is returned to its locked placement, the individual bins are available only to those that have a key.
Outward bound mail is a second concern for government services and tucking outward bound mail into the outside corner of the mail box defeats the aim of security.
A commercial security mail box will have a separate slot for outward bound mail that is secured and after the mail is put in that area it may only be reclaimed with a key, in most cases held by the mail carrier. If someone drops an item in and desires to have it back, they will have to hang on until the mail carrier shows up to open the outbound mail partition.
Dependent upon the size and number of government office buildings being serviced by the locking commercial letterbox, options might include service for between 2 or 3 to several dozen.
A lot like post office boxes in the postal office or in commercial mail delivery services, access could be available to each individual box via a rear door or the front side, depending on the wall into which it’s anchored. If at all possible, no one inside any of the offices are going to have access to anybody else’s mail box and security of the info can continue being at the highest level.