All engines ultimately produce HTML, so html is the only required field.
A plain-text alternative is optional but recommended: when both html and
text are present, the message is sent as multipart/alternative, which
improves deliverability compared with HTML-only mail.
The content a TemplateRenderer produces.
All engines ultimately produce HTML, so
htmlis the only required field. A plain-text alternative is optional but recommended: when bothhtmlandtextare present, the message is sent asmultipart/alternative, which improves deliverability compared with HTML-only mail.