Can i e-file after mailing in the federal return? it’s been 5 months, with no response in the status of my return

[Critter]

If you printed, ink signed and mailed in the return then do NOT mail another or switch to efiling ... doing so can delay the processing even longer.   The IRS was not processing mailed in returns for 10 weeks due to the virus situation ... they are just now opening envelopes again ... so all you can do is wait patiently as they play catch up.