can I send post ahead to Saint-Jean or to Santiago?

Yes, but ... we know of several examples of great disappointment: the Post Office is closed on the day of arrival, or the packages arrive after long wanderings or not at all. "What now?"

So it is important to ask yourself: do I really need all of this stuff?

Sometimes pilgrims send things ahead because it is forbidden to take them on the plane. It might be good to know that there are two good stores in Saint-Jean especially for pilgrims, with a wide range of equipment: Direction Compostelle and Boutique du Pèlerin. During the season these shops are open every day.

If you decide to send stuff ahead here are some tips:
addressed to Saint-Jean-Pied-de-Port:
Bureau de Poste
A l’attention de: *** (name, as in passport).
Poste restante
1 rue de la Poste
64220 Saint Jean-Pied-de-Port
addressed to Santiago de Compostela
Oficina de Correos 
a la atención de: *** (name, as in passport) (Peregrino)
Lista de Correos
Rua Orfas 17 

15703 Santiago de Compostela 


In Santiago post is stored two weeks. (It obviously helps if you put in the address: "Peregrino" = pilgrim). If you want to the post to be stored longer, you can send it to a private storage address: Ivar Rekve. This seems to be a good solution for smaller parcels. Bigger and heavier parcels might better be send through Bourricot Express. You can then pick up your luggage at Hostal Albergue "La Salle" in Santiago. More > Bourricot Express.
The Canadian Company of Pilgrims has made a list of Post Offices in Spain > Downloadable Guides > then click: Post Offices along the Camino Francés.