Attaching files to an email from the SD card

[GraemeT]

What I'd like to do is store Word documents on an SD card (which I haven't got yet because I need to know the answer to this question) in my 820 and be able to attach them to outgoing emails. Is this possible? I've checked out the 820 user guide. It doesn't seem to address this but says check out windowsphone.com for more email stuff, which I've done. That says attachments need to be on your phone. No kidding! Or actually, do they mean attachments must be in in your phone's internal memory? Thanks for your help.