I am glad you raised that question. I must say at the outset that this is not one of my research areas. However, I have read around the question in other cases. I will give you my thoughts, but they are thoughts that I am sure you will be able to improve upon.
I think seniors are an interesting question because we have an aging population and because we are in a situation where access to resources for the care of seniors is increasingly difficult to achieve. Several provinces are having problems in this area.
Consider prescription medication, for example. We know it is dangerous for seniors to go and pick up prescription medication at pharmacies, especially in winter. They have to go themselves because they have a prescription. Could there be a system whereby the Canada Post service centre could receive prescription medication and forward it to the individuals concerned the next day instead of having the pharmacy send it through its own delivery system or even by mail? Could that centre not become a community venue where the pharmacy would deliver medication so that people could receive it the next day? The service would be provided quickly and simply, and people would be pleased with it. Provincial departments could decide whether to offer the service to the public and participate in its funding, which moreover they are already doing with not-for-profit organizations.
There you have a way to find other funding sources. That is why I was talking earlier about a section on funding. There are a number of good ideas about how other public or private organizations can take part in the funding of Canada Post, but they are never considered. It seems to me this is an idea that should be explored.