The email appears to come from the Office 365 Team, telling you that your Mailbox is almost full and offering to add additional quota to your storage.
The email looks like the example below:
Notice that the senders email is not actually a Microsoft or Microsoft related address.
Also if you hover over the hyperlink, the actual address does not match the description shown in the email. The domain that you can actually see is not correct either, with a lower case L for the i in Microsoft.
If you click on the link, it will take you to what looks like a Office 365 sign in page:
However, the page is not using https, there is no padlock. The address is not a Microsoft related domain and the spelling of the two occurrences of Microsoft are not correct either: rnicrosoft and M1cr0s0ft.
Don’t be fooled.
This article was originally posted on http://www.winthropdc.com/blog.