Maybe I'm too resistant to change but please stop trying to be Google... the whole reason I prefer Outlook is for a UI that is not gmail.
Scrap current (new) UI, get **significant** feedback from users for a truly usable replacement UI.
Anonymous User commented
Agreed! Why is it that every "improvement" by every company seems to involve a major UI change that messes with users' workflow and generally looks uglier than the UI it replaced?
Ask users when they first get started in the new UI if they want one of 2-4 "visual experiences", then set their default settings differently. This way people can start with what they want, then adjust from there.
For example: I love gmail but my employer doesn't. So I tweaked the settings (reading pane hidden/sender images hidden/group by date off) so now it's visually similar to gmail - which keeps me happy.
My boss loves her folder structure and the reading pane, so she wants to see a whole different structure. She love the sender icons for example since she talks with customers all the time and wants to quickly get a sense of who's emailing her.
Give everyone a few different experience options at the get go (e.g: classic, streamlined, people-focused) that reflect that different people have different ways of interacting with their email. It will also encourage people to interact with the settings once they realize that they truly have a lot of options as to how they see their email.
The interface looks kind of crowded and isn't helpful to me as much as it is annoying. I just prefer a simpler, calmer, less colorful inbox. Or at least the option to have that.