I wasn't able to send my return in by the deadline. Am I still able to E-File today?

Using TurboTax you can e-file a 2016 tax return at any time on or before October 16, 2017.  A 2016 tax return can be printed and mailed at any time.

Also, there are not penalties for filing a tax return after the due date if you are receiving a tax refund.