Microsoft has again extended support for the classic Outlook app, giving users a little extra time with the aging Windows client. The brand now says that classic Outlook will remain supported until at least 2029, even if the new Outlook becomes the default experience in Microsoft 365. Enterprise clients won’t be forced to move to the new version of Outlook until March 2027.
Microsoft has been pushing the new Outlook app for a while now, and it shared its plan to phase out the old app more than a year ago. At the time, it was said that enterprise users would have to ditch classic Outlook by April 2026. But many business customers still depend on classic Outlook. By extending support, Microsoft gives admins more time to test the new app, adjust policies, and migrate line-of-business add-ins to the modern model.
Perpetual Office products, such as Office LTSC and Office 2024, also play a big role in this timeline. Office 2024 includes the classic version of Outlook and has a support period of 5 years, ending in 2029.
In practical terms, Microsoft will start pushing the new Outlook as the default in 2026 and will later remove classic Outlook from standard Microsoft 365 installations, but existing classic deployments can continue to run with security patches until at least 2029.
