Since the language was already changed back to English and the iPhone profile was reinstalled, use this order to force Outlook on the web to rename and refresh the default folders:
- Sign in to Outlook on the web.
- Go to Settings > View all Outlook settings.
- Select General > Language and time.
- In Language, select the preferred English option.
- Select Rename default folders so their names match the specified language.
- Select Save.
- Sign out of Outlook on the web.
- If English was already selected, change to a different language, save, then change back to English and save again.
- Restart Outlook and check the folder names again.
For the phone app, the app language follows the device language by default. On iPhone, check Device Settings > General > Language & Region.
If this is a work or school Microsoft 365 account, the Microsoft 365 display language can override Outlook on the web. In that case:
- Sign in to Microsoft 365 with the work or school account.
- Open Settings and select Change your language.
- Set Display Language to English and save.
- If that option is locked or unavailable, the organization’s IT administrator must change it.
If the language changed unexpectedly, also review account security settings because unexpected language changes can happen after account compromise:
- Change the password.
- Review sign-in activity.
- Enable two-step verification.
- Sign out of all sessions.
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