Microsoft popped up a prompt needing me to click "Next" during login to my hotmail and outlook.com accounts...
...so X-Notifier wasn't able to check for new email.
To clear this...
You'll have to Open a new tab, Goto hotmail.com and/or outlook.com, or live.com... Log in manually... and then click "Next" on the pop-up (that will clear it), and it will then go to your account...
...then X-Notifier will be able to check your account for new email.