If you open an email to send to someone, you'll see options at the top. Click on that and click on "Spell check as you type". All it does is underlines in red, words that are spelt wrongly. If you click on the underlined words it shows alternative spellings. Beware it seems to be an American spell check, so when it underlines word spelt correctly in English but not American, you can click on the word and then click on "add to dictionary" that way it remembers the correct English spelling. There is a way of adding an English dictionary but I haven't bothered.
