What version of Exchange are you on please?
The answer is version independant. You cannot attach emails in OWA. Although you can open email attachments in OWA, you will not be able to attach an email. Your setting in Outlook to attach the email history just doesn’t work in OWA…
I beg to differ… Using OWA on Exchange 2003 you can indeed attach documents and the e-mail thread is retained IF…. that’s the way it’s (the Exchange Server) is configured. My organization does it all the time (Systems support messages are sent from a shared OWA mailbox and attachements are sent on a regular basis).
If you select “Reply”, “Reply to All” or “Forward”, the message window that appears will contain (unless, as stated above, the server is configured to block it) the previous message(S) test and header, and there is an “attach file” icon in the toolbar…
If this is not the case, then the Exchange server admin may be able to adjust settings to allow….