OWA now supports Office 365 Sensitivity Labels, which means that users can apply labels to mark and/or protect messages with encryption just like they can with Outlook. The update adds to the ways that sensitivity labels can be applied to Office 365 content, with the next step being to achieve the same support for the other online Office apps.
The process of introducing Office 365 sensitivity labels to a tenant can be long and complicated because of the need to plan how to manage encrypted content. As you go through the process, don’t delete labels if they’ve already been used to protect content. Instead, remove them from the label policies used to publish information to clients. The labels will then remain intact in documents and other files.