It has been in Shenzhen China since June 3. China postman tried to deliver it to you on June 11 but seems failed.

You'd better call China Post service number 11185 to require them deliver again.

I'm the sender...I live in Italy.
Can I contact Shenzhen local post by email?
Not by phone please...

Sorry, they don't provide service through email. Could you contact the recipient and let him to call.