Seems a pretty obvious bit of functionality, but I can’t for the life of me see how to do it or find instructions anywhere. All I want is to get no email notifications from gitlab at all, but still receive the popup notifications from my browser when I’m on my computer. All the notification options seem to only allow you to decide what to be notified about, not where to be sent the notification. By contrast, GitHub has very clear checkboxes to switch off each notification type for different methods (email, mobile, browser etc)
I looked into your question and dug around in the GitLab issue tracker for a bit.
It looks like there is no such feature (yet) but there is an issue for it, if you wanna check it out: