Hello @Balakrishna Sudabathula thanks for the question.
To answer your first question- Yes, Azure Communication Services supports template-based email**.** You can use the Email client library to send templated emails from your application. The Email client library provides a set of APIs that you can use to create and send templated emails. You can find more information about the Email client library in the following ACS document Email client library.
Regarding your second question, Azure Communication Services does not validate the email domain address before sending the email. However, it is recommended that you verify the email domain address before sending emails to ensure that the emails are delivered successfully. You can verify your email domain address by adding it to the list of verified domains in your Email Communication Service resource. You can find more information about verifying your email domain address in the following document: Add custom verified domains to Email Communication Service.
Hope that helps
-Grace