If you lost menu bar, press alt key If you lost 'new message' button, press view>folders>folder pane header To restore SEND button, click 'new message' and then click View>toolbars>composition toolbar (again, if menu bar is not showing, press alt key)

Some of your response helpful thanks. I have recovered the menu bar. When wanting to send new message have gone to view composite bar but the send button is still grey while the spellcheck is showing okay

The send button is greyed out if the TO address is missing or incomplete or if Thunderbird is offline.