www.wysiwygwebbuilder.com

I need a custom HTML Editor software that my people can see the HTML reusable existing template
- Change/Swap the images
- Change content
- Save it and send it to email marketing tool

Is there any such software exists, can we do it using WWB

There is no standard solution for this, but technically it is possible to do this with WWB and custom code.

Note that some webhosts (for example, 1and1/ionos) do have a dedicated email marketing tool in the control panel.