Zebidee said:
The spell checker in Mail appears to be using a "US" English dictionary.
How
can I replace this with an "English" English dictionary?
You might be able to find a real list of English words on the web
otherwise you have to "train" it or edit the dictionary list,
both of which are long and painful austerities.
To edit or replace the list...
Open this file in Notepad and edit it:
C:\Users\*YourName*\AppData\Local\Microsoft\Windows Mail\UserDictionary.lex