Ravi,
Thanks for your comments, we are aware that we can use html email service, the question here is with respect to communities as it uses the "AEM Communities Email Reply Configuration - Factory configuration" with name points to "subscriptions-email" for configuring the from address and other communities related attributes for email notifications.
The problem here is in the back end adobe code they hard coded with the value "subscriptions-email" and to override this, it requires huge customization. We are looking for any options that help us us to achieve the functionality with minimal changes at configuration level, that we might missing.