The lock bolt is in the mailbox does not always withstand the encroachment of the feeder bullies. Too primitive its form is thin and the iron from which it is made.
But if you replace the stock bolt with steel plate cross-section 20×3 mm, bent as shown, so just the box, no one will open.
Recommend to read
“LASONIC” FROM CHEBOKSARY
Double car "Alison-nick-2" specially constructed for movement in urban environments. Therefore, before designing, I have formulated the main requirements that had to meet the future...
SATCHEL — NOT A FOREIGNER
Some just "containers" for books not used by students going to school, from stylish backpacks and briefcases to canvas bags, and plastic bags. But if high school students is allowed...