Correos, the Spanish mail, provides several services to pilgrims. The most useful is pack transfer along the trail. If you don’t want to carry all your stuff you can have them pick it up where you stay and transfer to the next place you are staying. You can carry a small day pack. This service is definitely in our future but for now we are still carrying all our stuff (32 pounds total for both of us).
Another service is to send a bag to the end of your walk, usually Santiago, and they’ll hold it for up to 45 days. We had things we needed only on the plane, like noise-canceling earphones, comfortable clothes, etc. so we put them in a suitcase and sent them on.
It is, for us, always a pleasure dealing with Spanish people. The Correos people we so nice and helpful. And we got a text two days later that the bag was waiting for us in Santiago. Of course, we already knew that because we had slipped an AirTag in the bag.