If it can't be any comfort to you, tampering with mail also happens in western countries, and France has a bad record for that. I have had parcels and various letters disappear, especially over holiday and X-mas season, when the mail hires extra workers.
In the Phils it seems to me that even ordinary mail cannot be distributed without a signature. Once I sent a card to my gf in Davao at her home address and it appears that the postman called SEVEN times to give it but she was at work every time. The eighth time her son signed on her behalf... So I write her at her office because they will always take the mail anyway!
