FYI: I have never in 5+ years of being invested in CUU received any mailings from CUU, so I don't know what circular you are talking about

You have to tell your broker when you signed up for their service you want to receive communications from companies you hold shares in. If you checked off the box that told them you don't want communications ( like proxies, info. circulars, notices for agm etc. ) you won't get any.