Applications can send notifications at any time, unless you don't allow them. To disable and turn off notifications for specific apps on HTC 10 and block notifications for these selected applications, do as follows:
1. Open the Settings app on your device
2. Scroll down to the Phone settings and touch to open the Apps settings
3. The list of all your applications should appear here. Simple open the application you want to block notifications.
4. Now, under the App's details menu, tap the Notifications settings
5. And make sure to toggle ON the Block All option.
6. From now on, you won't receive any notification from this app.