When you manage a template you can flag the complete template, a variation of it, or a language version, as "inactive". An inactive template is still returned and can be used as normal. However the "inactive" property of the response object will be true and the application contact email address will be notified.
If a language version that doesn't exist is requested the CTM will fall back to the English version of the template. The "fallback" property of the response object will be true and the application contact email address will be notified.
The emails sent to application contacts are managed within the CTM itself using the "Email Management" application. This set of email templates is created when the "Initial Setup" test in the goss.CommsTemplateManager.ImportApplication End Point is run.
The fallback, inactive and inactive & fallback emails should never themselves be flagged as inactive, but their body text and subject lines can be updated as normal.