After connecting, I will first complete the QSL using various electronic methods.
Then, I would look for their contact information in public places like QRZ, or simply ask them directly when we were communicating through a platform like Tonglian.
If the recipient prefers a paper card, I will confirm with them that the mailing address I have found is valid, and then mail the card.
Domestic first-class mail, excluding return postage.
If I haven't received the package within 7 days in this location, and a month in the destination location, I will contact the sender again to see if they need to resend it to an alternative address.