This ensures that the original message arrives completely intact at the recipients of the forward. They can even reply to it as if they had received the mail originally themselves.
There is a small disadvantage to forwarding as an attachment. Since the original message is not altered by default, you will reveal all the email addresses in the To: and Cc: headers. This can be avoided by taking some extra steps.
To forward a message as an attachment with KMail:
- Open the message you want to forward in KMail.
- Press F (think forward).
- Alternatively, you can also press the Forward button or
- select Message | Forward | As Attachment from the menu.
- Address and edit the message.
- Finally, click Send to deliver it.