Adresses Québec
Adresses Québec is a portal to multiples databases linked to the road network. There are also information about adresses and postal codes.
Many files formats are available.
There are two open databases on this site: AQ Reseau and AQ Reseau+.
Unformtunately, this site is in French only.
Consult
http://www.adressesquebec.gouv.qc.ca/ for more details.