No you do not mail anything to the IRS when you e-file. It is all done and transmitted electronically. However, if you file by mail, then you must attach any W-2's or 1099's that show tax withheld.
What is the Box Category you are reporting? see exception below.
If you are not excused by the detail reporting exception,
IRS requires details of your SELL transactions to be supplied on some Form 8949,
or on your other forms (e.g. consolidated 1099-B or spreadsheet) which have the same information and in the same manner as Form 8949.
This is so, even when the broker has sent details to the IRS already.
The exception does not include wash sales, since they have an adjustment.
Either way, if you choose to summarize only, you have to mail the transaction details to the IRS within three business days of IRS accepting your e-Filed tax return. (unless you have attached a PDF of the transactions details to your e-Filed return. TurboTax Online will ask for it).
Detail Reporting Exception:
if you summarize Category A or Category D, Form 8949 is not needed for transactions without adjustments. No mailing is necessary.