Outlook forward email with attachment

[TM]

Dear All,

Need some urgent help here. One of my user is
encountering some problem with email forwarding. We are
using pop mail in our office. And my user do a forward
email with attachment and remove the attachment from it.
After which he edit the file and reattach it to the
forware mail. After sending out the email, he realise
that the original attachment was attached together with
the revise copy.

Did anyone of you encounter this problem before? Do you
know what is the cause of it and how can it be fix?

Thanks in advance
TM