[exim] Varying message size limit according to sending host?

Hi -

Is it possible to vary the message size limit according to where the message is received from? I've had a bit of a look at this but it appears that message_size_limit is set globally - is this correct, or is there another way?

The background is this:
We have Exim gateways in front of an Exchange system. The Exchange hubs limit the message size that Exchange accepts inbound, globally. Our scanners relay via the Exim gateways. What I'd like to do is increase the size limit on Exchange (allowing a higher limit for internal traffic), increase the limit for the scanners on Exim (to match the limit on Exchange), and limit all the genuinely external traffic with a lower limit on Exim.

I hope this makes sense!

Thanks for any solutions/suggestions.

Regards

Richard
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Richard Rogers
Principal IT Officer, Client Technology and Applications
Information Services, Staffordshire University
Tel. 01785-353785