I received the following message August 28, 2014. "Hi, Officer Julie Smith from Internal Revenue Service and the hotline to my division is 415-251-6983. I repeat it's 415-251-6983. Don't disregard this mesage and do return the call before we take any action against you. Goodbye and take care." I checked the phone number and it is a landline in Ignacio, California. I did not reply to this call, as per the IRS website any correspondence from them would come via official post office mail.