Compose or Reply to a message to open the email composition window.
Click the Attach (paperclip) icon.
Use the finder window to locate the file that you want to attach to your email. Click on it once to highlight it and click on the Open button.
A visual representation of the file that you have selected will appear in the body of your message. Verify that this is the correct file before sending your email message.
Note: To remove the attachment, click once on the File icon or picture and press the Delete key on your keyboard.