Prefill templates is a concept to initialize the Body field in the Email Screen when you want to send emails manually. Contexts can define a single prefill template.
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Contexts have an Email Template attribute. This specifies the template used to send the emails sent manually. If you configure the Context with a prefill template, you should not use the same template to send the email, otherwise all content will be duplicated in the email because the Body field is added to the template via the variable $!mailBody. Or more generically, Email Templates and Prefill templates should not have overlapping content to avoid duplication of content in the email.
Instead, if you have a Prefill template, we recommend you create a template as simple as $!mailBody and select it in the Context's Email Template field.
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Prefill mechanism is only applicable to emails composed manually. Event Notifications or Workflow Postfunctions should be configured with regular, detailed templates.
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