To know how to fix when Outlook notifications not working, go with the followings:
Firstly, open outlook and go to the file tab menu. Select options from the pane. click mail from the left side. Once you select the mail there you will find a message arrival section, select all the options and press ok. next go to the start button click on settings, click on system. Left side of your desktop you will find some option from there select notification & action option. There you can see the view, turn it on and close the window.