Here's the thing. If it's from someone internal, we have instant messaging if say u want some kind of message instantly. If I get an email, I'm assuming I have time to action it. If I'm not busy, sure, I'll action it right away, but if I am and I see an email come in from someone internal not marked high importance, there's a good chance I'm not even reading it for like 2-3 hours maybe more. I absolutely hate when someone sends an email and a follow up like an hour later. If it's urgent, u need to convey that in some way, shape, or form.