Spell-check email in Mail on iCloud.com
If you’re using iCloud Mail in Safari or Firefox on a Mac, you can check a message for spelling errors using the browser’s spell-checking feature.
If you’re using a different web browser, check the browser’s preferences or menus to see if it has its own spell checker.
Do any of the following:
In Safari, choose Edit > Spelling and Grammar > Check Spelling While Typing.
In Firefox, choose Firefox > Preferences, then turn on “Check your spelling as you type.”
In Google Chrome, choose Edit > Spelling and Grammar > Check Spelling While Typing.
In Mail on iCloud.com, compose a new message or open a message you want to check.
Questionable spellings in the message are underlined with a red dotted line.
Command-click a misspelled word on a Mac, or Control-click on a Windows computer, then do any of the following:
Accept a suggested spelling: Choose the word you want.
Add the word to the spelling dictionary: Choose Learn Spelling or Add to Dictionary.
Repeat step 3 for each underlined word to correct all of the spelling errors in the message.
Safari offers additional spell-checking options, which you can also choose from the Edit menu.