Simonwalcal said "Just forgot the email and call the CRA to be sure. Use the phone number on a document you have (or that you searched up yourself), NOT the number in the email.
I have gotten memos from the CRA before, but it's generally to inform me that I have a message within my online CRA account (usually something tax-related). They will email you to inform you of unread CRA messages but they won't include much else for security reasons.
Good practice for anything like this (including online shopping) is to go directly to the source independent of the email. Because you never can know what new grifts the scammers will pick up on. "
This is a good general rule of thumb. Places like the government and banks won't give you much detail in an email, but might send you an email telling you to log in and check messages.
Don't ever click on a link for things like this. Log in using your normal/usual way, like stated above.
When in doubt, insist on things in writing/mail.