Microsoft Dynamics 365 Marketing doesn't offer a direct way to set preheader details for an email template through its user interface. The preheader is the brief text that appears at the very beginning of an email.

My suggestion is to consider incorporating a direct and intuitive method for users to set preheader text within the email template creation process. This would not only streamline the workflow for marketers and content creators but also elevate the impact of their email campaigns. By seamlessly integrating preheader customization into the user interface, Dynamics 365 Marketing would empower users to efficiently optimize their emails for engagement and responsiveness across various email clients.

Moreover, introducing a preheader feature could potentially alleviate the current need for users to implement HTML workarounds to achieve this functionality. Simplifying the process would enable marketers to focus more on crafting compelling content rather than navigating technical complexities.

In today's digital landscape, where every detail of an email can influence its success, the inclusion of a dedicated preheader field could be a game-changer. It would not only enhance user satisfaction but also contribute to the overall effectiveness of Dynamics 365 Marketing as a comprehensive email campaign solution.

I kindly invite you to consider this idea for future enhancements to Microsoft Dynamics 365 Marketing