Downloading attachments on A500

[cheese_aholic]

I have an Iconia A500, and am using their standard set-up with the addition of File Manager HD.
I access my email mainly via Outlook Web App, but am unable to download attachments.
When I click on the attachment it tells me 'download started' but then just sits there for a while before telling me 'download failed'
This is my first Android device - am I doing anything wrong??