Sending, receiving, and organizing email in Outlook.com
The behavior described while composing and sending email is not fully detailed in the available documentation, but there are a few known Outlook-related issues and settings that can cause confusing behavior when typing or sending messages.
For issues where Outlook changes language, characters, or text unexpectedly while composing:
- Classic Outlook replacing characters with question marks (extended or accented characters, symbols like ®, £, etc.):
- This is a known issue in Outlook for Microsoft 365 Version 2601 (Build 19628.20150+).
- Workarounds include:
- Use Outlook on the web or New Outlook instead of classic Outlook.
- In classic Outlook: go to File > Options > Advanced > International Options and:
- Uncheck Automatically select encoding for outgoing messages (Workaround #2), and/or
- Set Preferred encoding for outgoing messages to Unicode (UTF-8) (Workaround #3).
- If necessary, revert Outlook to the prior version 2512 (Build 19530.20184) using the documented Click-to-Run command, and temporarily disable automatic updates until the fix is released.
- Strange or mixed characters in message bodies or meeting requests:
- This can be caused by the Windows “Beta: Use Unicode for UTF-8 worldwide language support” setting.
- To work around it on Windows:
- Open Settings.
- Go to Time & Language > Language.
- Under Related settings, select Administrative language settings.
- In Language for non-Unicode programs, select Change system locale.
- Clear Beta: Use Unicode for UTF-8 worldwide language support.
- Restart the computer.
- New Outlook / Outlook.com auto-features that interfere with typing (for example, auto-capitalization or Editor behavior):
- In Outlook.com or new Outlook on the web, auto-capitalization and other Editor behaviors can be turned off while composing a message:
- Start composing a new message or reply.
- On the message toolbar, expand the toolbar (small down-arrow if it is collapsed).
- Select Message on the toolbar.
- Select Editor on the far right.
- Open Editor Settings.
- Turn off Enable Auto Capitalization and any other Editor options that are changing text in unwanted ways.
- In Outlook.com or new Outlook on the web, auto-capitalization and other Editor behaviors can be turned off while composing a message:
- New Outlook Editor language switching unexpectedly:
- There was a known issue where Microsoft Editor proofing/spellcheck languages in new Outlook for Windows could change unexpectedly (default language switching, languages disappearing, or order changing). This has been fixed service-side as of December 2024.
- If language switching was part of the problem, ensure the Editor language settings are now correct using the guidance in Check spelling before sending a message.
If the product reports that a message “cannot be sent because it has been altered,” this typically indicates Outlook or a related component believes the message content or encoding changed in a way that conflicts with its current settings or a known bug. Applying the encoding workarounds above, disabling problematic auto-features (such as auto-capitalization/Editor behaviors), or using Outlook on the web or New Outlook instead of classic Outlook are the supported mitigations in the current documentation.
For persistent or unclear send failures, use the official support channels for Outlook.com or Outlook to provide details (including version, platform, and exact error text) so that the product team can investigate and address the underlying issue.
References:
- Classic Outlook replaces accented and extended characters with question marks
- Strange characters are displayed in meeting requests, read receipts, and IRM messages
- Microsoft Editor proofing or spellcheck languages change unexpectedly in new Outlook for Windows
- how to disable "auto-capitalize first letter of sentence" on OUTLOOK.COM email please? - Microsoft Q&A
- Fixes or workarounds for recent issues on Outlook.com
- Fixes or workarounds for recent issues in classic Outlook for Windows
- Characters are garbled in email body
- Fixes or workarounds for recent Office issues