Where is intuit.ca picking up my OLD email address (prior year purchases/prior year filings) from?

I net-filed two 2018 returns yesterday. I received the confirmations from intuit.ca but they went to my old email address. I did not use this email address to purchase the download product (standard). I did not use this email address within the return (contact information for Revenue Canada).  Where is intuit.ca picking up this email address (prior year purchases/prior year filings)?  I want to correct this so that it does not happen again next year.  I will lose access to that old email account.   I did call the intuit support line, howwever, the agent did not know where the email address came from or how to change it. (incident# xxxxxxxxx). Thanks.