Taxes were completed in Turbotax back in April. Couldn't complete the e-file, so in a panic I paper mailed the extension form along with a check for the taxes. Check was cashed, but no other acknowledgement of acceptance was sent back to me. The finished tax return from April is still here on my computer, but not sure what to do next. E-file won't be an option. Should I just paper mail it in and hope for the best?
yes just mail it without the 4868. There is no official acceptance notification and no requirement to attach the 4868 when filing an extended return. The iRS got the payment so it got the 4868.
The IRS does not send any sort of letter or message to acknowledge that you sent an extension request. Your proof that you made a payment will be your own bank or credit card statement. When you prepare your tax return, make sure you have entered the payment you made when you sent in the extension form.
When you requested your extension you were supposed to pay your estimated tax due. Did you enter the payment you made into your tax return? Go to Federal>Deductions and Credits>Estimates and Other Taxes Paid>Other Income Taxes
You can still e-file unless you have some glitch preventing it. (That might or might not be fixable, depending on what the problem is.)
If not, print, sign and mail your return. Include any required documents per the instruction page (like W-2s and 1099s that have taxes withheld). Also, make sure Turbotax recognizes and includes the payment you made. Don't forget to sign. And don't forget you probably also need to print, sign and mail your state tax return. They go to different addresses in different envelopes. Be sure to include all required documents. Some states require that you include a printed copy of your entire federal return, some states do not require this.