How to make an email to be shown on the locked screen of my iphone?

I was playing with my phone and prob pressed something accidentally so now I hear the sound of the email but it does not show on my locked screen anymore. Please help. I want to be able to see my emails on the lock screen as before

Throw the phone and get an Android

Go to Settings
Notification center
scroll down to mail
select your email
the select what you want, either banners or alerts
you will also be able to choose an alert sound
and scroll down a little bit, it will say show on lock screen, and switch that on