attachment blocking with exchange-server

hey tecys

again i have a question.

im running a exchange-server 5.5 on a
win 4.0 server. the question now is is
there a way to block server-side
attachments like .vbs because i get very
rid of tellin my users not to doubleclick on
vbs attachments. i know there is a way
client-side but i wana block the
massages by server!
any solutions form me?

regards
da4id