[German]Since late January/early February 2026, users have been complaining that Outlook can no longer recognize umlauts and displays them as question marks. Microsoft appears to have recently fixed this issue in Outlook.
Bug since February 2026 known
German blog reader and IT service provider Peter S. contacted me via email on February 3, 2026, reporting that "for the past few days" he had been receiving an increasing number of reports from various customers stating that umlauts in their sent emails were suddenly appearing as question marks.
In response to my blog post Microsoft 365: Werden Mails mit den Zeichen ( & ä gelöscht?, blog reader Florian (on February 4, 2026) left this comment. There, too, customers noticed that emails sent with umlauts sometimes appeared in the sent items with only a ? in place of the umlaut. According to this reader, the problem occurred when the recipients had a Microsoft tenant on U.S. servers. I reported on the issue described above in my German blog post titled Outlook erkennt keine Umlaute – Problem bei Microsoft bekannt (can be read with the build in translate feature).
Microsoft has fixed the issue
On February 6, 2026, Microsoft confirmed the issue in the support article Classic Outlook replaces accented and extended characters with question marks
and recommended using Outlook Web Access (OWA) or the new Outlook app as a workaround.
Examples of issues reported to Microsoft include the registered trademark symbol (®), accented characters (é, ü, ñ, etc.), the pound sign (£), umlauts, and other non-ASCII symbols. According to Microsoft, this only affected Outlook 365 version 2601 (Build 19628.20150 and higher).
Microsoft has now updated the support article as of March 6, 2026, stating that this issue was resolved in the public updates released on March 10, 2026. The following Outlook 365 builds include the fix for the first time:
- Version 2601 19628.20252
- Version 2602 19725.20164
- Version 2603 19822.20032
Thanks to the reader for the tip. Question for those affected: Have you received the affected update for the above-mentioned build of Outlook 365 Classic, and has the issue with umlauts being replaced by question marks been resolved?
