How can I know if I have mailed an ordinary parcel?

You go to the original receiving and sending office to fill out a list, but the reply time of the list is usually about one week. Or you'd better tell the recipient the package number (the number below the barcode on the receipt) and ask him to check it at the local post office. It's definitely impossible to lose it. Generally, it is a problem in the delivery process.

I can't find the ordinary package, but it will arrive within 15 days. If it hasn't arrived in a month, it is probably lost, or the recipient can't be found, and it is on the way back to you. You can only use the receipt given to you by the post office to inquire about the whereabouts of the package. The post office will give you a written reply about a month later, and the result is who signed it or couldn't find it (that is, lost it).