Also received message from 703-662-8086 about two hours earlier.
Definitely IRS scam - got the same mechanical messages that I'm in big trouble for not filing taxes. transcript of voicemail (xfinity):
"You're subjected to receive this message. Even if your number is out of state for the national do not call list. Our attempts to notify you why certified mail. Have it turned on the word resulting into a lawsuit to be prosecuted in your name on a council fraudulent I no tax filing. You know your tax outstanding contact our order department on 703-828-0605. I repeat it's 703-828-0605 before any legal actions are taken to forcefully recover the amount unpaid. Thank you."