Hi,
This KB show how to unblock http://support.microsoft.com/default.aspx?scid=kb;en-us;829982&Product=out2003

Regards

>To "protect me" Outlook 2003 blocks non-Office extensioned attachments.
>These include .app, .chm, .exe, .hlp, .prg and around 50 others.
>
>There is no way to override this, at least according to the "Help". Does anyone know if true?
>
>According to the Help, people should send blocked extensioned files by changing their extensions, for example MyFile.exe to be sent as MyFile.exe_Extra.
>
>I'd be happy to take responsibility for MY OWN protection. I don't mind the initial protection, but I'd sure like to be able to change that list! I bet that a virus can.
>
>comments?