I've tested on your site, it seems like that email and system notification also seems work, you can check my attached screenshot below.
if you referring email notification, i realised you have a lots of pending email didn't send out yet, may i know do you have setup cronjob from your server yet?
You can read this documentation here :
https://stackideas.com/docs/easysocial/administrators/cronjobs
Hope this will help.
If you need help on this, perhaps you can provide us with your Cpanel access which can setup cronjob from your server then i will help you setup on this.