Outlook converting attachments to notepaid with zip.txt extension

[Carlena]

Our office just upgraded to Outlook 2003. When I send an
attachment, if it is a large attachment, it gets converted
to a notepad document and re-identified
as "ATTACHMENT_OR_CONTENT_BLOCKED [original name of
document].doc.zip.txt"

This has happened with a Word document and a PDF
document. The recipient is unable to open the document.
I have sent the document to myself so I could see what the
problem is and when I try to open it, it opens in notepaid
and there is a message on the first line which
states "05/25/2004 15:33:03 Original attachment [original
name of document].pdf.zip) was Quarantined. The original
attachment was blocked from delivery due to current
attachment blocking rules. You can safely save or delete
this replacement attachment.

This does not happen on my assistant's computer (and we
are both on Microsoft Exchange Server) and she is able to
send attachments with no problem.

Please help.

Thanks.

 

[neo [mvp outlook]]

Any type of 3rd party software installed that can scan outbound messages?
(would focus on desktop first since the description indicates that assistant
doesn't have this problem sending through the same exchange server)