8453 is a cover page that you print and mail to the IRS along with some other document that the IRS needs by mail, after you e-file.  The most common form that needs to be mailed to the IRS is form 8332 dependent release in custody cases, but there are a few other things that may be needed.

Print a copy of your return and read the instructions carefully.  If you need to mail a form to the IRS and don't, your refund could be delayed or you could be audited.

It sounds like Turbotax might have sent out a bunch of emails by mistake.  See FAQ below.

However, you should still check your return to make sure you don't have a form 8453 that needs to be mailed to the IRS (most often, due to a custody issue). 

https://ttlc.intuit.com/replies/7101541