The buyer's is from Saint-Paul on Réunion island. His shipping and PayPal addresses are almost identical, but the first says "Réunion" and the other – "France". The problem is that the Czech Post don't ship registered/insured parcels to Réunion – and all other options are at much, much more expensive.
I know Réunion is a French department, so both addresses are technically correct.
So, would the parcel reach the destination if we just put France instead of Réunion?
Comments
https://www.upu.int/UPU/media/upu/PostalEntitiesFiles/addressingUnit/reuEn.pdf
A problem you may run into if you print off labels online - parcels to Réunion require a CN22/23 as the territory is outside the EU's customs union, but the Czech Post website may not ask you to complete the customs fields for a parcel to France. You may have to ship it via a post office.