This front-end development (SA Email Builder) can be integrated with a specific project that allows you to create a responsive email for different goals: marketing, communication, etc..
The project which took severals months of development make it possible to create very easily with drag and drop a responsive email 100% online. You have this advantage combine with another one which is to generate cross-client browser HTML (gmail, outlook, etc..) thanks to the generated JSON which can be sent to MJML engine. The website to see more details about it is available here: http://email-template-builder.kevingermain.com/
Link of demo: http://sa-email-builder.kevingermain.com/