Yes, absolutely. It dates back to the 1930s or 1920s, I don't remember. Before I was born, in any case. You could vote by mail. However, it is used very little. We received about 55,000 ballots in the mail, 35,000 of which were from Canadians overseas. So it's a very small number.
On October 22nd, 2020. See this statement in context.