creating rule to filter swearing

[James]

Hi,

I work for a <20 user co with SBS2003 and exchange and im trying to set up a
rule that checks the users outgoing email for swear words, eg sh*t etc etc
and if it contains them replies with a message like please do not use company
email to swear. but i have tried to setup a sever rule and i doesnt work? i
know of something regarding it only replying once, but as you can tell this
would need to happen evey time someone swears

thanks