You can customise the way you receive notifications such as push, email or in-app from your Notifications center.
To adjust your notification preferences: Click on your profile badge  and then select My notifications :
From Notifications deliver options you can toggle on/off the different ways you can receive notifications:
We try to send each notification only once depending on your status. For example; you would receive push notification if you were online and an email notification if you were offline, unless you specified otherwise in your notifications settings.