It is a simple feature, and it might look like a minor issue, but I believe it is an important way of improving clarity, diversity & inclusion.
In a global economy, we constantly work and communicate with people from other cultures and countries. With that, some names might be difficult to type for people who are not used to their orthography. Even though it is an unintentional mistake, some people might feel not included if they have their names constantly misspelled in emails.
So, my request is that Outlook "validates" the people names on the body of emails against the people listed on the TO/CC lines. If it encounters a name that seems to be misspelled (e.g.: Alexander vs. Alexandre), it could underline it in blue, so the user can identify a possible mistake and correct it.
Besides eliminating confusion caused by the typo, it would make the receiver feel more included by being referenced by their correct name.