Received a VM this morning from this number Message says:  "This is to inform you that IRS is filing a lawsuit against you. To get more information about this case file, please call immediately on our department number 806-543-7821.  I repeat 806-543-7821.  Thank you."  Also received another call and VM with same message from a different number, 719-580-3402. Guess they figure if they call from different numbers, you'll eventually call back.  Can't fool me :)  IRS would send a written notice for anything.