[exim] disclaimers :-(

Someone had the bright idea that those pesky disclaimers at the bottom
of emails are a good thing. What is common practice and how'd I
implement it in exim? I assume that this ought to be done for external
recipients only and not for local email. I am sure this has been asked
before, if so please point me to the right documentation.

And if this is a bad idea (I think so) I'd like to know it and why. :-)

Thank you,
Jeroen