kumomta/docs/reference/message/set_data.md

message:set_data(payload)

{{since('2024.06.10-84e84b89')}}

Replaces the message body/data completely. It is your responsibility to ensure that the content is well-formed, has canonical CRLF line endings, and uses appropriate transfer-encoding, otherwise the system will misbehave when delivering the message.

See also:

• msg:get_data()