What should I do if I receive an email saying that I want to declare or return the goods?

You'd better go to the post office for on-site consultation.

In this case, your mailing items are generally beyond the scope of personal reasonable use.

Or, all items have to go through formal customs declaration procedures, but the cost is too high, so it is not recommended to operate.

Or, return the excess to foreign countries and pay the refund fee.