Email Notifications for Tasks

Is anyone else having problems with receiving email notifications when assigning a task? Some of our users are receiving email notifications and some are not. Project status is executing. Org and individual email notifications are set to receive. Users are Workers and I am a sys admin. I'm receiving zero and there has been a mix amongst the workers regardless of whether I assign the task or have someone else assign the task. It's all over the place. I have a support ticket in but they referred me to my IT. IT traced emails and the "missing" email notifications are definitely not coming to us.