To send an email:
Click New Mail on the toolbar.
In the To, CC, or BC box, type a user name, and then press Enter. Repeat for additional users.
Type a subject.
Type a message.
To add an attachment, click the paper clip icon on the toolbar, select the file, and then click OK.
or
Drag a file into the attachment window at the bottom of the compose view.
Click Send.
For more information, see Composing Email.