[exim] Help in Catch mail going out for a specific user

I am struggling in catching all the mail(of a specific user) going out. I can catch all incomming mail for that user.
We are using exim 4.20 and the users information is stored in a database including the filter (As a field in the database).
I have tried various different things including

# Exim filter
if error_message then finish endif
if first_delivery then
unseen deliver mailaddress
endif

But it works only if the person receives mail and not when he sends the mail.

Thanks for any help