The IRS has sent an email to a business owner asking you to download a PDF file containing the alleged charges against you. The IRS doesn’t email taxpayers; they send certified letters via the United States Postal Service. The number in the message’s closing is a legitimate IRS phone number. If you call it and explain the email, the person on the other end will immediately call this scam out for what it is. Any time you get an email form the IRS and suspect it isn’t on the level, send it to phishing@irs.gov and delete the original.”]
Source: https://www.csoonline.com/article/2874403/deconstructing-an-irs-phishing-scam.html