This page tests the exact things your website needs — reading content, saving a form, sending email — and tells you in plain English which one is failing and why. Nothing here is visible to your visitors.
This page is not linked from your site's menu. Nobody will find it by browsing — only someone who has this exact address can open it. If a check below creates a test enquiry, it will say so, and it is clearly labelled so you can delete it from the admin's Enquiries tab.