Message center notifications not working

Hi, can someone help me with this issue? I have checked my email setup with my hosting provider, that confirms everything is in good condition. The newsletter works. Autoresponder works. Notifications when vendors get approved also works through email notification.
BUT: nobody is getting email notifications for messages inside message center!
Does anybody have an idea on this?
Would be very glad to get an input here.
Many thanks and kind regards

Hello, David!

Please check if the Message Center notifications are configured and turned on.

If you will not be able to fix the issue, please copy your request to and we will help you.

Best regards,