How to disable autocorrect in Windows 10 Mail?

Windows 10 Mail will not let you turn off autocorect. The only things you can do are switch language of the email and/or add unknown words in email options.

When composing a new email, put options and in there is spelling. Tick the first option and it should be OK. Although such as small letters on the beginning of a sentence and then corrects me.

Go to Options/Spellings and tick "Hide all proofing marks". That's how I got rid of this nuisance.