For a return from France, the package must be dropped off at a Colissimo drop-off point or a post office.
You can follow this link to find the nearest drop-off points: https://www.laposte.fr/particulier/outils/trouver-un-point-de-retrait-ou-de-depot-colissimo
Returns from Denmark, Estonia, Portugal, Sweden and Latvia must be dropped off at a DPD drop-off point. Here is the link to find the nearest drop-off locations: https://www.dpd.com/be/fr/
Returns from Lithuania, Luxembourg, Slovakia, Slovenia, Hungary, the Netherlands, Poland, Spain, Germany, Austria, Croatia, Belgium, Greece, Romania, Italy, Ireland, Bulgaria, and Malta must be dropped off at a local post office.
Returns from Andorra, Cyprus, Réunion, and Australia must be sent via DHL.
Here is the link to find the nearest drop-off points: https://locator.dhl.com/?l=en&countryCode=fr
A return from Switzerland is made via FedEx.
Here is the link to find drop-off points near you: https://local.fedex.com/fr-ch