Dated UI and email template language but does the job

We use it as the email marketing platform for our company. We create email flows, design templates and modify code. We have to do our own versioning of our templates on a git-based platform outside since Marketo doesn't do this. The UI unfortunately looks like it was from the 2000s of web and is rather unintuitive but gets the job done once you become familiar with the platform. From an engineering perspective Marketo uses velocity templating language which is a Java-based templating engine so it's got a learning curve and is a bit of a pain to use. But the integration with the tokens of user variables is convenient for each user and testing and saving users is also convenient to do.

I would love it if had some sort of foundational email library so that we can ensure our emails work with Outlook Desktop because that is still a pain to debug and manage separately.