Classic Outlook for Windows is expected to be supported and available untilat least 2029. Although the new Outlook will become the default from April 2026, companies and users with Office LTSC/Microsoft 365 subscriptions will continue to have access to the classic version for several more years.
Important details:
  • Support until 2029:Security updates and support will continue for classic Outlook until at least 2029.
  • Transition phase (April 2026):From April 2026, the new Outlook will become the standard, but you can still switch back to the classic version.
So there's no need to rush into changing right away, as the classic version will remain secure for a long time to come.