Used FedEx Express Saver to mail federal tax returns to IRS.

I used FedEx Express Saver to mail federal tax returns to IRS. Do I have to mail it again using one of the following as stated on IRS site? : 

1. FedEx First Overnight
2. FedEx Priority Overnight
3. FedEx Standard Overnight
4. FedEx 2 Day
5. FedEx International Next Flight Out
6. FedEx International Priority
7. FedEx International First
8. FedEx International Economy