Hi,
for email digest users only receive once a day and will not listed at email queue.
for else notifications, users will get email notifications by cronjob running.
so you need to changing cronjob interval at your cronjob setting at your server site.
maybe every 30 minutes, because cronjob will be executed 150 email per cron running.
for cronjob setup, you need to asking your server support about it.
and here the jomsocial cronjob URL documentation:
https://documentation.jomsocial.com/wiki/Setting_Up_Cron_Job
Regards