Update add-custom-verified-domains.md

Author: anmolbohra97

articles/communication-services/quickstarts/email/add-custom-verified-domains.md

@@ -26,7 +26,7 @@ Before provisioning a Custom Domain, review the following table to determine whi
 | | [Azure Managed Domains](./add-azure-managed-domains.md) | [Custom Domains](./add-custom-verified-domains.md) | 
 |---|---|---|
 |**Pros:** | - Setup is quick & easy<br/>- No domain verification required<br /> | - Emails are sent from your own domain |
-|**Cons:** | - Sender domain is not personalized and cannot be changed | - Requires verification of domain records <br /> - Longer setup for verification |
+|**Cons:** | - Sender domain is not personalized and cannot be changed<br/>- Sender usernames cannot personalized<br/>- Very limited sending volume.<br />- User Engagement Tracking cannot be enabled <br /> | - Requires verification of domain records <br /> - Longer setup for verification |
 
 ## Provision custom domain
 To provision a custom domain, you need to: