Only you can change your email address.
See this TurboTax support FAQ for updating your TurboTax account - https://ttlc.intuit.com/questions/2578442-how-do-i-change-my-turbotax-account-email
You have to sign onto your 2018 online account using the exact same user ID you used to create the account.
Close all TurboTax windows on your web browser (including this one). Copy and paste the account recovery website link onto a new web browser window and run the tool.
Use this TurboTax account recovery website to get a list of all the user ID's for an email address. Run the tool against any email addresses you may have used - https://myturbotax.intuit.com/account-recovery
If none of the user ID's received will access your 2018 account, then use the option shown in blue on the account recovery website, "Try something else"
Did you e-file your tax return and was it accepted?
You complete your tax return by finishing all 3 Steps in the File section. In Step 3, to e-file your tax return, you must click on the large Orange button labeled "Transmit my returns now".
After completing the File section and e-filing your tax return you will receive two emails from TurboTax. The first email when your tax return was transmitted and the second email when the tax return has either been accepted or rejected.
Use this TurboTax website to check the status of an e-filed return and if it was either accepted or rejected - https://turbotax.intuit.com/tax-tools/efile-status-lookup/