Yes, you can temporarily disable alerts of a sourcing board.
Follow these simple steps to disable the alerts.
Go to the “My Sourcing Boards” page where you can see all your sourcing boards.
Click on the 3 dots of the desired board and click on the "Manage Alerts" option. This will redirect you to the “Configure Board” page of the sourcing board.
Go to the "Alerts settings" section. Select the "I do not want to receive the alert" radio button and click on the "Save and Take me to my Board" button to save the changes.