Configuring preferences and options in Outlook on the web for business
Hi Joey,
Regarding your concern, the personal dictionary controls spelling recognition, but the change from COs to Cos is an AutoCorrect replacement. Therefore, adding the word to the dictionary doesn't trigger a spelling warning, but it will not stop the capitalization change.
Because you are using Google Chrome, please test whether the browser’s spell-checking service is involved:
- Open another text field outside Outlook, such as a blank web form
- Type COs followed by a space
- If it changes there as well, open Chrome Settings > Languages > Spell check > temporarily turn off Check for spelling errors when you type text on web pages, and test again
Should there be any updates about the issue, please share them in the comments of this post. I'm happy to assist you further.