Corrupted attachment

[Clundey]

I have an external internet address set up in my system recipient list. When I email a Word document to that address, everything is fine. If I add that address to my personal contacts OR to a contact list in the public folder, and email the same document (addressing it from either contact list), it becomes corrupted when it reaches the recipient. It doesn't seem to matter what format, PDF's get corrupted as well (thats all I've tried so far)

I've tried setting mail type to HTML, Plain Text and Outlook rich text both on client and server to no avail.

I'm using Exchange 5.5 sp4 and Outlook 2000 sp2

Thanks