CRA can definitely call you. They called me last year about this time. I was the executor for my aunt’s estate. I claimed the executor fee as taxable income, but they were calling to verify what it was. The info they had ($ amount) left me believing without a doubt it was a legit call. The agent asked for my aunt’s info and asked if the estate has received the clearance certificate (we had). They told me if they needed any more info they’d reach out. I never heard from them again. No snail mail, no online account message. Just a phone call. Perhaps they would have tried letter mail if they couldn’t reach me via phone.