How to stop emails in Salesforce?

The Email Notification can be turned off or the level can be changed using the below steps

1.       From Setup, click Email Administration --> Deliverability.

2.       Set the Access Level.

No access: Prevents all outbound email to and from users.
System email only: Allows only automatically generated emails, such as new user and password reset emails.
All email: Allows all types of outbound email. Default for new, non-sandbox organizations.

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