Are you talking about the oath invite email or email on how to download e-certificate?Well i got mine just a day before my oath day, while the online tracker was updated more than 2 weeks before my oath. I called CIC as suggested on the portal, still they had no damn clue why i never received while they do see the status as email was sent at least a week before (not even in spam or promotion) then sent a web form couple of time, then i got it immediately after i sent my second web form inquiry (not sure if it was a coincidence).