Comment by wallstop
3 hours ago
Anecdata, they might have had a system error. My Microsoft account that I use the free tier OneDrive on had the same email sent (you're over x% full, consider upgrading!). I suspected everything you did - eventually I logged in after verifying the email - nope, 5% usage or so.
I then went and deleted more stuff, but my money would be on a reporting glitch than a malicious money campaign.
A system error on a file storage system makes it even worse! But easy to imagine after the recent report on Azure https://news.ycombinator.com/item?id=47616242
Sorry, what I meant by "system error" was more "notification system error". Not error as in "data loss", error as in "reporting".
Myself–and many redditors–got this erroneous notification too. I don't think Microsoft ever sent out an "Oops, sorry, you don't actually need to pay us" correction though.