This is a question that would be handled best by TurboTax Support. You can contact them by starting here:
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Interesting ... to efile you had to enter the code sent to that email so in the 24 - 48 hours after filing when the email would have been sent that email account was no longer active ?
So that this doesn't happen again update your email address now :
To update your TurboTax account, see this TurboTax support FAQ - https://ttlc.intuit.com/questions/1900724-how-do-i-update-my-turbotax-account-information
To update your TurboTax Advantage account, see this TurboTax support FAQ - https://ttlc.intuit.com/questions/1900547-how-do-i-update-or-confirm-the-information-in-my-turbotax-...
And now for the 2018 return ... it cannot be efiled any longer ... it must be printed, ink signed and mailed. The rejection reason is immaterial now.