EmailMessage message extension

A message extension for the EMAIL channel. If no value is defined for the subject and/or htmlContent attributes, the default values of the message model are applied.

Attributes	Type	Description	Optional	Default
subject	xs:string	Message subject.	Yes	“”
htmlContent	xs:string	Default message content if PreferredContent is set to RICH_TEXT or BOTH.	Yes	“”
textContent	xs:string	Default message content if PreferredContent is set to SIMPLE_TEXT.	Yes	“”
preferredContent	PreferredContent	Sets the default message content.	Yes	BOTH