According to this email, your email service has prevented the delivery of new messages to your inbox.
The message, which purports to be from the “Microsoft E-Mail Service”, claims that you can click a button to review the undelivered messages and “choose what happens to them”.
However, the email is not from Microsoft and, despite the green label, it certainly was not “sent from a trusted sender”.
Instead, the email is a phishing scam designed to hijack your email account.
If you click the “Review Messages” button, you will be taken to a scam website that asks you to login with your email address and password. After entering these details, you may then be redirected to a genuine Microsoft website.
Criminals can now use the login credentials you submitted to gain access to your email account and any linked services such as online file storage or app stores.
Once in, they can use your account to send spam and scam emails in your name. If they can access linked services as well, they may be able to make app store purchases via your account, read and download your stored files, and collect even more of your personal information.
Using the account and the information they have collected, they may be able to impersonate you and perhaps even steal your identity. They may also be able to hijack other online accounts you own by using the reset password option, which often uses a password change email sent to your account.
Phishing campaigns like this take many forms. Be wary of any email that claims that you must click a link or open an attached file to deal with a supposed account problem.
Always access your email account by entering the address into your browser’s address bar or via a trusted app. If there really is an account issue that you need to deal with, you will most likely be informed after you login.
An example of the scam email:
