[Area 1] Add note (cloudflare#23159)

Author: Maddy-Cloudflare

src/content/docs/email-security/migrate-to-email-security.mdx

@@ -7,6 +7,10 @@ sidebar:
 
 This page aims at showing you how to perform Area 1 actions in [Zero Trust Email Security](/cloudflare-one/email-security/), and new terminology introduced in Email Security.
 
+:::note
+Your Area 1 data and configuration settings are available in Email Security.
+:::
+
 ## Invite users
 
 In Area 1, you [invite users](/email-security/account-setup/manage-account-members/#add-user) by logging in to the Area 1 portal and inviting members.