There was a bit of panic shooting through me as I listened to the recording, which said that the IRS was "suing" me. When I calmed down, I thought a bit and came up with this: the IRS doesn't sue someone--they audit them. At least that's the first part (happened to me in the 1980s).
So I concluded that it was a phony call. Thirteen months later, July 2017, in comes another phone message. Pretty hilarious. They said that the IRS is "filling a lawsuit"--not filing but filling, like adding to a gas tank--against me. And then the kicker: I "tried to do a fraud" against them.
Good English, eh? Some criminals become dumber over time.