docs(ddx): add information how to validate email address (#4743)

* docs(ddx): add warning about email validation

* docs(ddx): validate email

* Apply suggestions from code review

Co-authored-by: Rowena Jones <[email protected]>

---------

Co-authored-by: Rowena Jones <[email protected]>

Author: bene2k1

pages/dedibox-account/how-to/update-email.mdx

@@ -19,7 +19,8 @@ Every Scaleway Dedibox account is associated with a specific email address. In t
 
 - A Dedibox account logged into the [console](https://console.online.net)
 
-1. Click your username, next to _logged in as_, in the top right corner of the Dedibox console. Then click **Account information** in the pop-up menu. The account information page displays.
+## How to update your email address
+1. Click your username, next to **_logged in as_**, in the top right corner of the Dedibox console. Then click **Account information** in the pop-up menu. The account information page displays.
 2. Click **Update** next to your email address:
     <Lightbox src="scaleway-dedibox-console-update-email.webp" />
 
@@ -30,4 +31,15 @@ Every Scaleway Dedibox account is associated with a specific email address. In t
 
 You have now linked your new email address to your Scaleway Dedibox account.
 
+## How to validate your email address
+
+<Message type="important">
+  To enhance the security of your Dedibox account and ensure a smooth experience, it is required to verify your email address.
+  If you have not yet verified the email address linked to your Dedibox account, please complete the steps below.
+</Message>
+
+1. Click your username, next to **_logged in as_**, in the top right corner of the Dedibox console. Then click **Account information** in the pop-up menu. The account information page displays.
+2. Click **Validate my email** next to your email address.
+3. Follow the instructions to validate your e-mail address.
+