@Critter-3 wrote:
NOTHING is mailed when you efile any return.
Well actually...
There are about 8-10 specific (and rare) situations where you must mail the IRS a paper original of something after you e-file. In these cases, Turbotax will advise you in the filing instructions, and will prompt you to print a form 8453, which is a cover sheet that you mail to the IRS with the required form, usually within 3 days of e-filing.
A Roth conversion is not one of the cases that requires an original document. For routine tax returns, you don't mail anything after e-filing. And, now that the IRS has opened amended returns for e-filing, there is likewise no requirement to mail paper originals unless you are in one of those limited situations.