The package was returned

I need some help to understand what’s going on.

I sold a pair of shoes to a person in a neighbouring country. The sale was completed and I got the money.

Today I got an email from the courier company that the package is ready for pickup at my place. There are many scammers who send similar emails so I didn’t click the link and went to check directly with the company on their website. It seems to be legit but strange, I usually get sms for all packages I get.

No information from the buyer.

What do I do? Do I need to check with the buyer and ask why they didn’t pick up the package? Do I just list the item again?