3449002 - The "sendNotification" API doesn't display error when user doesn't exist

When working with the "sendNotification" API, you enter a valid user ID and it works correctly.
Instead of user ID, you type some random as "xyz" then also notification is successful. You expect a message as "No User Exist" can be displayed.

SAP Analytics Designer 1.0

This the current design. To perform the checking , it needs to take all the user information from BW backend beforehand, which will cost additional time and lead to performance issue. 

Please make sure to enter valid users for the API.

KBA , LOD-ANA-AD , Analytics Designer , Problem