My phone is only at present a Samsung Galaxy S 111 mini but when I click on the apps icon then on the email icon all I get is a blank screen does anyone know what I may have done wrong if anything and how to correct it.

This may be a stupid question but have you actually set up your mail account in the mail app?

Yes as I have been sending and receiving emails and am normally able to see what is in my in box.This has only just started

Which app is it? The standard Google mail app that comes with Android, a Samsung app or some other mail app?

Have you checked that all your account details are still correct? Always possible that something has zapped the settings and it's no longer connecting to your mail server.

Can you log onto the e-mail service via a web browser on your computer and verify there are e-mails in your inbox on that? If there are none there then something may have screwed up and deleted everything. I presume the phone app is not set to download messages then delete them from the server?