You can find this in the ‘organisation management’ tab – ‘my organisations’ – [choose organisation] – ‘enable periodic validation’
Choose the frequency with which you want to receive periodic validation reminder e-mails. These e-mails are sent to the top-level administrator and all user administrators.
The frequency can be changed via the ‘organisation management’ tab – ‘my organisations’ – [choose organisation] – ‘frequency of periodic validation reminders’.
You can change your permissions via 'customise preferences'.