Move Indicator Notification panel to extreme right in XFCE desktop session
Solution 1:
Right click on the panel and choose 'Panel' -> 'Panel Preferences'. Then go to 'Items' and add a seperator that you move with the arrows to the desired place. Close that window and do another right click now to the area where the seperator is located, enter the 'Properties' and choose 'Expand'.
Solution 2:
Change separator style to Transparent if you don't want to see it.