For my own habit, I will install an app in Store based on some factors. I will type the keyword related to the app I want, then I will select from the search suggestions. Then I will focus on the top 15 and check its screenshot, description and most important thing is to check its ratings and reviews. I will mark 2-3 apps in mind. After this, I will install them to check which one is the best for me.
For you, you can try keyword Email, Email app, you will get one within top 10.