Outlook Express gone Crazy

I installed outlook express for one user and when the user sends email the recipient receives two emails. The one that has the users message has the Subject XXX on it and the other email has NO SUBJECT but has the following inside the body of the email
“[Filename: FREE_xxx_sites.TXT.pif, Content-Type: application/octet-stream]
The attachment file in the message has been removed by eManager.”

Does anyone know why this happened?