[EXIM] fail message with custom text?

Hi,

I am wondering if exim has the facility to fail a (possibly frozen)
email, with a custom bounce message. I think what I'm looking for is
something like:

exim -Mfail message-id "this mail was rejected because foo"

I see that exim -Mg fails a message, but doesn't allow for specifying
the failure text.

I'm using exim 2.12

Thanks,
Dave
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Dave Holland -=- Systems Administrator, Incyte Genetics, Cambridge, UK

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