I think you may mean Efile instead of mail your tax return. If you did it online you probably tried to efile it. If you used the Online version you can check your efile status here
https://turbotax.intuit.com/tax-tools/efile-status-lookup/
When you efile you get back 2 emails. The first email only confirms the transmission. The second email says if the IRS (or state) Accepted or Rejected your efile. And check your spam folder for them.
When you log into your account you should also see the status and if it was Accepted or Rejected, Started, Printed, Ready to Mail, etc. What does it say for 2020?
