I _think_ you need to use a system filter to do this.
Have a look at the exim home page(http://www.exim.org),
the documentation is pretty thorough and there are examples.
I have something like this as my system filter, it rejects overlarge messages
and archives
a particular users mail to disk.
Can any one give me any hints on how to if possible setup exim such that
if it recieves an email that is say over 100K that it routes it over a
smart host instead of trying to deliver directly
Alex
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