If you decide Site Mailer isn’t for you, you can unsubscribe using the General Settings screen.
To deactivate your Site Mailer subscription:
- Go to WP Admin.

 - Navigate to Settings>Site Mailer.

 - Click General Settings.

 - Scroll down to the Account section.

 - Click the ellipses 
on the right hand side of the Account area.

 - Select Deactivate subscription.