You can create a new Email using the REST API, full documentation here: https://developers.marketo.com/rest-api/assets/emails/ The most common process though is to put Program Tokens inside the email and populate the Program Tokens with new content via the API.  Program Tokens docs: https://docs.marketo.com/display/public/DOCS/Understanding+My+Tokens+in+a+Program Program Tokens API: https://developers.marketo.com/rest-api/assets/tokens/ ... View more