My boyfriend sent me a letter by EMS from Xi 'an, and it has been five days since it arrived. I don't know what to do with the bill number.

Hello, Landlord: If there is no express delivery number, you can find the parcel just by saying the telephone number of the recipient or the telephone number of the sender. You can get the waybill number if you can provide the telephone numbers of the receiving and sending parties correctly, but if you can't provide it, you can only know the situation of the package.