This morning I had not one, but THREE emails telling me to review the attached invoice from Microsoft and remit payment.
You want to be a good citizen and pay money if you owe it. And with all of the changes lately in the IT world with the cloud and Office 365 there might be a chance that you pay for a subscription. However, the same warning you always hear from your IT folks applies: NEVER open emails or attachments (even if it's just a Microsoft Word document) from someone you don't know.
Microsoft Office products have the ability to help us automate tasks that we do on a regular basis by using macros. If you've ever used a macro in Excel or Word, you know how easy they can make life. However, they are very powerful. You can open, change, and save files using the macros in Word and Excel. So don't do it. Ever. There's a good chance that a macro is embedded in that "invoice" that will cause you and your company great pain.
If you ever have ANY question about an email, check with your IT staff BEFORE opening it. In most cases, you can recognize that it's not for you and just go ahead and delete it directly.