Hello!
I'm Yasllame. I'm here to help and clarify.
This answer has been translated automatically. As a result, there may be grammatical errors or strange words.
What is causing automatic capitalization?
In Windows 11, some languages and keyboard layouts activate automatic capitalization rules when they detect:
New line
Start of sentence
Use of language-based autocorrect
When you press Enter and start a new line, the system interprets it as the start of a sentence and forces the first letter to be capitalized as soon as you press Space.
How to fix (official and functional solutions)
Option 1 — Disable automatic corrections in Windows 11 (recommended)
Open Settings
Go to Time & Language
Click on Typing
Disable the following options:
“Show text suggestions as you type”
“Autocorrect misspelled words”
“Automatically capitalize the first letter of sentences” (if available in your language)
These options control exactly this behavior in the web editor.
Option 2 — Check the keyboard language
Settings → Time & Language
Language & region
Under Keyboards, check:
If more than one language is active
If you are using a layout that applies advanced autocorrect
If possible, temporarily test:
English (US)
Default Portuguese (Brazil)
Then, test again on Outlook.com.
Option 3 — Confirm if the problem occurs only in the browser
Test:
Another browser (Edge, Chrome, or Firefox)
Incognito window
If the problem does not occur in another browser, it may be related to:
Grammar correction extensions
Language extensions
Assisted writing tools
Temporarily disable these extensions to test.
Important note
In Outlook for desktop (classic), this setting exists and can be controlled in Word options (Editor).
In Outlook.com (Hotmail), there is no built-in control, as the editor is browser-based.
I hope this information has been helpful! If you need anything else, I'm here.
Sincerely,