Outlook on the web
- Not available
Outlook for Windows
- In the message, click the Review tab and then click Spelling & Grammar.
- Respond to suggestions.
To keep the Spelling & Grammar command always within reach, you can add it to the Quick Access Toolbar.
Outlook for Mac
- In the message, click the Options tab and then click Spelling.
- Respond to suggestions.
- Close the Spelling and Grammar window.
See Check spelling and grammar is Office 2016 for Mac for more information.