Upvote:2
Post offices outside Taiwan aren't acceptable. It's not a question of mailing something in, the post office bank is the one who is going to pay you the winnings.
That said, you can have a representative take the winning receipt:
A winner need not collect the prize money in person. Such person as is entrusted by a winner to collect his or her prize money should present his or her own ID card along with the winning person's ID card and the winning uniform invoice at the post office in order to receive the prize money. finance ministry
So you can mail the receipt to a trusted person, who could transfer you the winnings later.
Whether that is worth it depends on how much you win...but you can check if you're a winner just by looking at the winning numbers.
Why not just check and then make the decision about whether it's worth it, later?