[Exim] Keep copy of outgoing messages

hi all:

Is it possible to keep a copy of all outgoing messages from a specific
e-mail (tech support) so that we can build a knowledgebase from advice
sent out by our tech staff. I want to be able to centralize this rather
than having a copy kept on the user's workstation I would like a copy
kept on the server.

If this is possible how do I configure exim to accomplish this?

best regards
imran