Waited till last minute, completed taxes, efiled. Then TTax told me I have to mail in my return. It's 11:47 pm, cant get to the post office in time. Am I now late?

I waited until the last minute to efile. Then Turbo tax told me that I have to mail in my return as well. It's too late to make it to the post office before midnight. So am I late since I efiled in time, but I did not mail before midnight.