I used a disc to file and have the email acceptance from TurboTax dated May 17, 2021.
Be aware that the e-mail is "NOT" generated by TurboTax. It's actually generated by the IRS computers and is sent back to you "through" TurboTax. I guess that's so TTX can alter it with their logo and stuff.
Also be aware that two physically separate e-mails are generated for the federal return, and two more physically separate e-mails are generated for each state return if a state is e-filed.
The first e-mail simply indicates the tax return was successfully transmitted to the IRS. That does not mean the IRS computers actually received it. So if this is the only e-mail you have, that's not good enough.
The second email informs you if the IRS accepted or rejected your e-filed return. If accepted, that's the e-mail you need as proof that you filed, and proof that the IRS not only received it, but that they also accepted it as filed. That's the e-mail you need as bottom line proof.
Also, if you will open your tax return and elect to save it as a PDF, then in that PDF file you'll also have a page called something like "Electronic Postmark" which is hands-down proof the IRS accepted it as filed.
Finally, understand that just because the IRS has accepted your e-filed return as filed, does not mean they agree with it. If it gets flagged and they change something that changes your refund amount, then it's perfectly possible you just flat out will not be able to see it on the irs.gov/refunds site; since you won't have any way of knowing the changed refund amount.
As back logged as the IRS is, it's really no surprise here. Heck, I personally know 2 folks who still haven't received their 2019 tax refunds. (It was 3, but one of them finally got their refund a few weeks ago for 2019 taxes.)
