Using the New Outlook for Mac for personal email and calendar
Hi,
You can try this: In the new Outlook for Mac, the settings for autocorrect are now managed through macOS rather than directly in Outlook. Open the Apple menu and select System Settings (or System Preferences on older macOS versions), then go to Keyboard > Text. From there, uncheck Correct spelling automatically to turn off autocorrect system-wide. If you only want to disable it in Outlook, open a new email, click Edit on the top menu bar, hover over Spelling and Grammar, and uncheck Check Spelling While Typing and Correct Spelling Automatically.
Kind regards,