Why is my email inbox suddenly empty

I opened my email (Sky email) yesterday, and despite having several emails saved in there and new emails, my whole inbox is empty. I can read them on my iMac but not on iPhone. My iOS is up to date, I've deleted email and set up again and done a hard reset of my phone (iPhone 7) ...

Sent items are there, I have sent myself emails which show there, but don't come through to my inbox.

Any help appreciated.