Filtering before MS Exchange

[mbox mbarsalou]

I personally use bogofilter at home and was considering pitching it to
an organization that is currently using MS Exchange.

I am fairly sure that they are not wanting to get rid of Exchange, so my
thinking is gravitating toward using bogofilter in a gateway machine
that delivers the mail to the Exchange server.

What are some opinions from the group here?

Aside from the distaste some might have for MS Exchange, is this a
viable option?

If this is a good idea, what should the gateway machine look like?  What
services need to be on it and what are some good methods for determining
the required hardware.  I was thinking something like Sendmail,
procmail, bogofilter.  Alternatives? 

We take small positive steps toward the light. :)

Mike B.