Blue Mail is actually one of the best-rated e-mail applications for Android. This application is currently holding a 4.6-star rating in the Play Store, and it offers quite a few features, not to mention that it looks really nice as well. You can choose between Material Design & Lollipop layout, while night mode is included here as well, same goes for rich text signature. You can attach your Outlook, Gmail, Yahoo Mail… and other accounts to Blue Mail, while the app also offers exchange support.