Add email authenticity note

Author: AlexFilipin

articles/active-directory/governance/customize-workflow-email.md

@@ -94,6 +94,9 @@ Emails sent out using Lifecycle workflows can be customized to have your own com
 - A verified domain. To add a custom domain, see: [Managing custom domain names in your Azure Active Directory](../enterprise-users/domains-manage.md)
 - Custom Branding set within Azure AD if you want to have your custom branding used in emails. To set organizational branding within your Azure tenant, see: [Configure your company branding (preview)](../fundamentals/how-to-customize-branding.md).
 
+> [!NOTE]
+> The recommendation is to use a domain that has the appropriate DNS records to facilitate email validation, like SPF, DKIM, DMARC, and MX as this then complies with the [RFC compliance](https://www.ietf.org/rfc/rfc2142.txt) for sending and receiving email. Please see [Learn more about Exchange Online Email Routing](/exchange/mail-flow-best-practices/mail-flow-best-practices) for more information.
+
 After these prerequisites are satisfied, you'd follow these steps:
 
 1. On the Lifecycle workflows page, select **Workflow settings (Preview)**.