There are three ways to turn off email alerts in Applications Manager:-
1. Stop all actions (Disables all actions in general):
Navigate to Admin--> Action/Alarm Settings and uncheck the "Enable Action when alarms are generated" box.
2. Stop all actions for specific monitor groups/monitors:
Navigate to Monitors-->Monitor group view.
Select the monitor group for which you need to turn off alerts. (If you want to choose specific monitors, click on the '+' sign and choose the required monitors).
Select 'Disable Actions' from Action drop-down box.
Click 'OK' button in the alert box that appears on the top of the page.
Click on the monitor for which you need to turn off email alerts.
Click on 'Configure Alarms' option under the "Host Details" box on the right hand side.
Choose the attribute for which email alerts need to be turned off (Health/Availability/Specific attribute).
If you want to turn off Health or Availability email alerts, click on 'Configure Health'/'Configure Availability' button. Move email actions from 'Associated Actions' box to the 'Available Actions' box.
If you want to turn off alerts for specific attributes, move actions from 'Associated Actions' box to the 'Available Actions' box.