Starting from 3.0.0.0, Administrator can decide whether On-site and E-mail notifications are ON or OFF by default for new members. You can set that in the backend of your site. Navigate to WP Admin -> PeepSo -> Configuration -> Notifications
The administrators can control the default email notification intensity setting for new users. This is especially useful if you don’t want your community to spam the users too much unless they explicitly say so. Setting it to something like “1 hour” as default might be a good starting point.
Neither of the new settings applies to post owners, as they auto-follow their own posts (until unfollowed manually) and have a separate profile preference to control notifications about reactions.
Administrators can disable ALL e-mail notifications for a given user. You can set that in the backend of your site.
Navigate to WP Admin -> Users
Click Edit user you want to disable their E-mail notifications and then find: Unsubscribe this user from all e-mail notifications
Click, and that user will have their e-mail notifications disabled.