Administrator can decide whether email 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 -> Advanced
Locate the Email panel and find Don’t subscribe new members to any e-mail notifications option.
Set it to Yes and all new members will have their e-mail notifications disabled by default.
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.