https://litmus.com/blog/a-guide-to-rendering-differences-in-microsoft-outlook-clients
The link above is to an article on the different rendering possibilities for different versions of outlook. It is lengthy and complex even though it’s just an overview! For clients that have issues with the way their email is displayed, or not displayed, or particularly for design oriented clients interested in email marketing the fact that so many features are either supported or not supported means that the client that expects adherence to tight design will be frustrated and ultimately disappointed. This is an expectation that needs to be managed.