To set or change the default proofing language in Outlook, please do as follows:

1. In the Mail view, click Home > New Email to create a new email.

2. In the new Message window, click Review > Language > Set Proofing Language. See screenshot:

3. Now the Language dialog box comes out, please click to select the new language you will set as default in the Mark selected text as list box, and click the Set As Default button. See screenshot:

4. In the popping out Microsoft Outlook dialog box, please click the Yes button to go ahead.

5. And then click the OK button to close the Language dialog box, and close the new email without saving.

So far, you have changed or set the default proofing language to the specified one in Outlook.

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