I filed my Federal Tax on 2/22 and mailed it out via USPS certified mail on 2/25, but IRS tracking refund status site still has no info. on my refund. What's the delay?

It might be that the severely short staffed IRS has not begun to process it yet.

 

TurboTax will not know anything about your mailed return, and will continue to show “Ready to Mail” on your account.  TurboTax will not know that you put your tax return in an envelope and took it to a mailbox.  TurboTax does not get updates on mailed  (or e-filed) returns.

 

Wait about 4 weeks from when you mail a return and then you can check the status on the IRS site. https://www.irs.gov/refunds

 

State returns have to be mailed to the state.

https://ttlc.intuit.com/questions/1899433-how-do-i-track-my-state-refund

 

If you mail a tax return (or a payment) to the IRS, it is a good idea to use a mailing service that will track it like UPS or certified mail so you will know it was received.