It's not likely to be an unsolicited email from MS. However, MS does send emails if one subscribes to the various newsletters it creates, so perhaps this is what has happened. I get emails from MS regarding new products and updates to programs, not that I originally signed up for them. It seems I missed unchecking the box where the offer was made, though I don't mind getting the newsletters as they have been useful and informative.
Another reason MS may send an email is in response to a direct request from a customer. Depending on the circumstances, MS my reply by email with solutions to persistent issues, etc, or to product enquiries that fall outside the FAQs. Such an instance occurred when I lost the product key to my copy of Windows 8 after a HDD failure... being the copy was purchased and downloaded directly from MS, and I could not retrieve the original email with those details, the product key was refurnished to me via another email.
So there are circumstances where MS does email customers, but if it's unsolicited and seeks information of any kind, then it is best to ignore it once reported to MS.