I got the same robo-call today in Pasadena CA. The message had two grammatical errors. IRS always writes to you, usually several times over several months, even years, before they sue you in tax court.
I have received a call from 202-241-8373 this morning around 9:13am. said that IRS filling a lawsuit against me so they want me to call their dept. 202-241-8373 immediately