I too received a call/VM. When I called the number to give them a piece of my mind the number they left on the voicemail is a NON-WORKING Number. Big surprise!
This is clearly a scam, the IRS would not contact you by phone with a fake digitally created voice. You would get officially endorsed mail correspondence.
I received a voicemail from this number also. Womans voice saying the IRS was preparing a lawsuit against me and I needed to contact them for information about it.
I too received a call from this number with the same message you're all talking about at 4:25 this afternoon. Clearly a scam and do not proceed with what they are claiming.