Got a call from this number today at 8:37AM (PST). It was an automated female robotic-like message (think first version of Siri) informing me that this is my final notice about a lawsuit the IRS filed against me. To call 313-327-3030 for more information.
This is a SCAM. The IRS will contact you via MAIL to set up a paper trail and PROOF of informing. DO NOT FALL FOR IT. Please file a report to federal authorities about this if you're called!