How to open unsafe attachments on Outlook Express 6?

I am trying to open an attachment on my Outlook 6 but an error is appearing on the top of my mail. The error is;

OE removed access to the following unsafe attachments in your mail
This message is sent by my other account on other computer so I know that the file is safe to open.
Even if I resend my email, I am still encountering the same error. Please help me on how to open the file.
My Outlook Express is running on my Windows XP Service Pack 1.
Thank you.
