That is a standard 'form letter' for a landing interview for an Inland applicant. If at any time in your processing you mentioned to your VO that you might have a hard time 'flagpoling' or updated your address for inside of Canada it may have triggered this letter to be sent to you. Even some outland applicants that receive their COPR inside of Canada are unable to 'flagpole' and require an office landing to officially land.
I would not worry too much about getting an email reply back from them. If you have already spoken to CIC and they have identified you as officially landed and your COPR / Passport has been stamped, signed, sealed and sent off for processing of your card via CBSA you should be perfectly fine.