add period after prerequisites

Author: ddouglas-msft

articles/communication-services/quickstarts/email/send-email-smtp/smtp-authentication.md

@@ -17,7 +17,7 @@ This article describes how to use a Microsoft Entra application to create the au
 ## Prerequisites
 
 - An Azure account with an active subscription. [Create an account for free](https://azure.microsoft.com/free/?WT.mc_id=A261C142F). 
-- An Azure Communication Email Resource created and ready with a provisioned domain [Get started with Creating Email Communication Resource](../create-email-communication-resource.md)
+- An Azure Communication Email Resource created and ready with a provisioned domain. [Get started with Creating Email Communication Resource](../create-email-communication-resource.md)
 - An active Azure Communication Services Resource connected with Email Domain and a Connection String. [Get started by Connecting Email Resource with a Communication Resource](../connect-email-communication-resource.md)
 - A Microsoft Entra application with access to the Azure Communication Services Resource. [Register an application with Microsoft Entra ID and create a service principal](/entra/identity-platform/howto-create-service-principal-portal#register-an-application-with-microsoft-entra-id-and-create-a-service-principal)
 - A client secret for the Microsoft Entra application with access to the Azure Communication Service Resource. [Create a new client secret](/entra/identity-platform/howto-create-service-principal-portal#option-3-create-a-new-client-secret)