Strange characters are displayed in meeting requests, read receipts, and IRM messages


In Microsoft Outlook and Outlook for Microsoft 365, some recipients receive email messages that contain a mix of characters in various languages in the text body. The messages may take some time to load.

This issue can occur in the following media:

  • Read Receipts
  • Email Recalls
  • Meeting Requests
  • IRM email messages


A beta Windows Unicode UTF-8 support setting is enabled by the sender. Outlook doesn't support this setting.


To prevent this issue from occurring on newly created items, the sender must follow these steps:

  1. Open the system Settings window. To do this, select the Settings button in the notification area of the Taskbar.
  2. Select Time & Language.
  3. Select Language.
  4. Under Related settings, select Administrative language settings.
  5. In the Language for non-Unicode programs area, select Change system locale.
  6. Clear the Beta: Use Unicode for UTF-8 worldwide language support check box.
  7. Restart the computer.