Variables in components

Hello,

I'm very pleased with myself that I managed to display the name of the Screen (cutting off "Screen_" from the beginning of the name) with this formula: Last(Split(App.ActiveScreen.Name;"_")).Result

However, as we use multiple tenants in my organisation, I would like to have the e-mail address, the user is logged in with, in the header. I created components for the header and the footer. But I don't yet manage to set a variable or reference a variable that's created on start in the component. I tried creating an output property (named varMail) and even managed to set it as the user's email address. But I don't manage to reference it

This is what the header and footer looks like, in case you're curious.