I may be missing something here, but I can't find how to define multi-part emails that include both text and HTML versions. As I understand it, multi-part emails have better deliverability than either plain text or plain HTML. Besides that, I'd like my members to see HTML emails when they are able, and the text version when their email client does not show HTML. Is there a way to define multi-part emails, and if not, could this be implemented in a future version? Thanks.