Some users are confused by the behavior of Ctrl+F in Outlook - sometimes it brings up the Find dialog, other times it Forwards the message.
When the cursor is in the message body, Ctrl+F brings up the Find and Replace dialog.
When the cursor is in the message header area, it opens a new copy of the message for Forwarding. If you use Forward as attachment (Tools, Options, Preferences tab, Email Options button) the message will be added to a new message as an attachment.
Other shortcuts whose behavior varies based on where the cursor is:
Ctrl+K - this resolves address when in the header area or opens the Insert Hyperlink dialog when in the message body. Use Alt+K to resolve addresses instead.