I am just an fellow TurboTax user and TurboTax will electronically send your completed tax returns to the Federal Government for free through the internet or you can choose to print them and sign the paper copies and mail them yourself. They will also send your State Returns to your State and it costs about $19.99 for them to send them electronically for you.
No, TurboTax does not mail the tax return(s) you will need to do that if you are unable to e-file your tax return. See this TurboTax FAQ for step by step instructions on how to print and mail your tax return(s): https://ttlc.intuit.com/community/printing/help/how-do-i-print-and-mail-my-return-in-turbotax-online/00/26258.
Now if you can e-file and want to change to the e-file option please follow these steps in this TurboTax FAQ: https://ttlc.intuit.com/community/e-file/help/how-do-i-change-from-mail-to-e-file-in-turbotax-online/00/26985