Your Mail app can sort your emails into different categories, but you don't have to use them if you don't want to.

Signing out of Mail on iPhone doesn’t actually take place in the mail app. It takes place in the settings app of your iPhone. The option to sign out of remove mail used to be under accounts and ...

which will affect any links you tap outside of Safari like in an email or message body. You can also pick a new “Contactless” app, a result of Apple opening up the NFC chips inside the iPhone ...