General UX Thoughts
Could use better UX - the many colors made it confusing - reminds me too much of inbox.google.com
- some more differentiation
- making attachment icons smaller
- keeping colors streamlined

First off, thanks for taking the time to provide the feedback! I just wanted to let you know that we actually have some options to disable/adjust some of the things you addressed.
I would recommend trying to do the following
1) Click the gear in the top right
2) Toggle off the Sender Photos and the Attachment Previews.
Hope that helps!
David Los