While Slack has supported Azure Active Directory previously today Slack announced on their blog support for Microsoft’s Office 365 apps like Word, Excel, PowerPoint, OneDrive and Outlook. Slacks new integration with Office apps and files, includes a new Outlook calendar and mail app, an updated OneDrive app, and the ability to preview Office files directly in Slack.

Slack and Microsoft have made a significant improvement to email space. Outlook mail integration, with the ability to bring emails straight into Slack channels, a new Outlook add-in and a new Outlook calendar app. The new Outlook calendar app for Slack brings in all your meetings and calendar invites into the messaging service along with meeting invites that arrive. The Outlook calendar app will even set your Slack status automatically based on your calendar, and it will add “out of office” to status if you’ve enabled it in Outlook.

Slack is also enabling full previews of Office files like PowerPoint slides, Word documents, and Excel spreadsheets. New OneDrive improvements allow you to preview Office files without even opening them.

Both Slack and Microsoft Teams have been going head-to-head to try to win over new customers but, in this case, bringing a new customer great customer experience is important to both Slack and Microsoft. Microsoft launched its free version of Teams to rival Slack, but I am not sure how good that is doing and maybe Microsoft see this as a better idea. I would like to see more Slack integration with OneNote sooner I am also interested to see if this is a space where Google might launch a messaging product.