The emails appear to be from the IRS taxpayer advocate service and include a bogus case number. They may include a message saying your 2013 income is flagged for review due to a document processing error.
Recipients are directed to click on links leading to web pages that solicit personal information.
Do not click on those links or respond to the email. You're asked to forward the scam emails to the IRS.
Additional information: http://www.irs.gov/uac/Tax-Scams-Consumer-Alerts