This sounds like a legitimate email, there are a number of instances that would trigger this notification. We take the privacy and security of our users very seriously and that's why we notify you of any activity involving your personal information. Please see the FAQ below for additional information.
https://ttlc.intuit.com/replies/4838253
If you suspect tax related identity theft, follow the instructions in this FAQ:
https://ttlc.intuit.com/replies/3301430