that claims to be Microsoft attempting to inform users their Office account email storage space is almost full and to prevent incoming/Outgoing mail from getting bounced back, to click the supplied link to add an additional 10 gigs of free and mandatory storage. This of course is an obvious scam to phish your password as the link takes you to a fake Office 365 login screen.
We here at SUPERAntiSpyware recommend you simply delete this email, and do not click any links within the email. If you have been scammed by this email, immediately change your Office 365 account password and consider looking into changing your spam settings to avoid future spam emails such as these. Remember, if you do not recognize the sender address, do not open the email, and also if you do open an email always hover your mouse pointer over the emails links to see where they’re trying to take you.