[rocketphish]

I got one of these calls earlier in the year as well. I called Revenue Canada directly to ask if they had called me, because I got a suspicious-sounding voicemail message. They said that they will never initiate correspondence by telephone, and that they will always send a letter in the mail first. The only exception is if you have an ongoing open case with them and you were requested to call them back with information. They said it is always best to ignore any calls purporting to be from CRA, unless you are expecting one. They said they will eventually send you a letter if you fail to call them back for some reason.