How to deal with lost package

Registered Airmail - enquiry of any damage, delay or loss package should be raised within 3 months upon shipment;
EMS - enquiry of any damage, delay or loss package should be raised within 3 months upon shipment;
SF Express - enquiry of any damage, delay or loss package should be raised within 1 months upon shipment.

Actual time for tracing any package would take around 2-3 months, depending on the destination postal service.