KMail when using Breeze Widget style for Qt4 looks out of place. Everything is big and boxy. The list of folders not take a lot more space to fit. There is a lot of white space.

KMail should also have a Breeze dark color theme to better suit the Breeze Dark color theme systemwide. Currently, KMail seems to use black for background, blue for links and white for text. This doesn't look great under Breeze dark which is more greying than pitch black.

Reproducible: Always

Steps to Reproduce:
1. Apply breeze widget style and color theme
2.
3.

Actual Results:  
KMail is boxy, too much white space, colors messed up

Expected Results:  
KMail takes appropriate space, better color theme for dark UI