Type in the recipients email addresses in To or Cc fields. “Expand Names” provides a quick lookup to your personal address book when you are typing. It can lookup for name, part of email address to full email address. But those email addresses should already exist in your address book. The expansion will be shown as you are typing as below.
You can select the recipient and it will be highlighted by blue. If you want to delete it from sending, you can click on the cross at the right hand side as shown below.
After all, you can input the Subject and Text. And then you can click “Send Message” to send. You will be directed back to the Inbox and notified the message was successfully sent.