Turn off Spell Check in Apple Mail?

You are moving in the right direction 👍

But you will need to go System Preferences >> Keyboard

In image below from macOS 13 Ventura , so you will need to modify exactly where to look in Keyboard on your computer

Turn Off " Automatically correct Spelling "

Understand, doing this is a System Wide Setting not just Mail or Safari

Every app has its own setting for this found in Edit > Spelling in Grammar. Turn it off there too.

Good catch and a bad oversight here 😂