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Is there a fix for the Outlook special character display bug?
The Technical Issue
Users are currently reporting a rendering error within Microsoft Outlook where German umlauts (Ä, Ö, Ü) display incorrectly as question marks. This anomaly surfaced in early February 2026 and affects both outgoing emails and items in the “Sent” folder. The corruption breaks professional communication standards and impacts readability.
Preliminary technical analysis indicates the error stems from character encoding mismatches. While the text data exists, the client fails to interpret the specific byte sequence for these special characters. This typically points to a conflict between the sending server’s encoding protocols and the receiving client’s interpretation settings.
Temporary Workaround
You can mitigate this issue by forcing the Outlook client to use a universal character set. This solution is effective for approximately 90% of standard email use cases.
To apply this fix:
- Navigate to File > Options in your Outlook client.
- Select the Advanced tab.
- Scroll down to the International Options section.
- Change the “Preferred encoding for outgoing messages” from Western European (ISO) to Unicode (UTF-8).
While effective for direct emails, this client-side adjustment has limitations. It often fails to resolve character corruption in emails generated by third-party automation tools, such as DocuWare. In these automated scenarios, the encoding headers are defined by the external software, rendering the Outlook setting irrelevant.
Microsoft’s Official Stance
Microsoft Support has acknowledged this behavior as a global service incident. Their internal diagnostics confirm the fault lies within the Microsoft 365 backend, specifically affecting tenants hosted on US-based servers. Emails routed strictly through local German providers (like Strato or Outlook.de) remain unaffected.
The engineering team is actively developing a patch to rectify how the servers process regional characters. As this is a server-side infrastructure failure, extensive troubleshooting on your local machine is unnecessary. The official advice is to wait for the automatic resolution from Microsoft’s deployment team.