You can use Forward to send a mail message to someone else. Forwarding a message includes all file attachments, whereas using Reply preserves the body text and does not include the attachments.
How your message is forwarded can be set up in Preferences>Composing. You can select whether to include the original text of the message and message header To/From and Subject header details in your forwarded message, or you can select to include the original message as an attachment to your email.
Open the message to be forwarded.
On the toolbar, click 
. A compose window opens. The text of the forwarded message appears in the body unless you have chosen to forward messages as attachments in the Mail Composing preferences.
Enter addressees in the To:, Cc:, or Bcc: fields.
Optionally, add a few lines of new text at the top so that the recipient knows why you decided to forward it.
Click Send.