Spellchecker is a useful tool helping you to avoid misspellings and other mistakes when composing new messages.
To check spelling of your message, do the following:
Compose your message and click on the "Check spelling" button below.
Spellchecker underlines all misspellings. Click on the underlined word to view possible alternatives. If any fits, you can select it from the drop down list.
It will replace the original misspelling and will be displayed in a green color. If you want to send your message with the performed changes, click on the "Accept changes" button.
If you don't want to send your message with the performed changes, click on the "Leave spellchecker and discard changes" link.