From answer by TurboTaxMayKay1, "TRANSMITTED means it was sent to the IRS and is awaiting ACCEPTED or REJECTED. The IRS will check that name matches social security number, the AGI and other things. Until you get the notification that is it accepted by the IRS, it will not be processed."
To check your e-file status you can go to the following link:
https://turbotax.intuit.com/tax-tools/efile-status-lookup/