Email

First you will need to set up your mail account with the Mail app.

To do this go to Settings > Mail > Accounts > Add new account. Select your email provider, log in, once your account is connected you will see a series of switches that allow you to turn on mail, contacts, notes etc. Turning them on will connect those services. Turn on the mail switch.

Your email should now be connected to the mail app and you can delete the app for your email provider if you want to.

See this Apple support article for more info.

Hope that helps!