Ninja If any user listed below logs in before the Cron is executed, the email digest will not be sent to that user.
Please see above message on Pending list. Pending list would not be cleared. So you have to wait for next section.
Also i can make a test to register myself on your site and then wait for 3 days as per your settings to get an email.
Please note the max email per cron is 100 and email limit depends on your server for each day, JomSocial can not overrule the server email limits. In case the email limit over the Users will not get email digest.