Unattended Outlook Mail Merge using UIPath


I am new to UIPath,Please can you help me to create unattended robot for mail merge functionality.

I have created one robot using some click functionality,this robot is working perfectly fine attended way but i want in unattended way.
Main.xaml (98.2 KB) This is the robot which i created.

I have enabled Simulate property for both click and type into.
Still it is not working.
And also if i enable:
Click ‘Mailings’: Click generic error.” Error message is displayed and robot stops in first step.