[Exim] Reject an email with a user-defined message

Lets say that Exim doesn't automatically deliver or send message (-q has not
been specified), and crond regularly runs a program that checks each message
in the queue for virus infection (just like exiscan).

If a virus is found, this program should send an error message back to the
original sender. What would be ideal is if exim could be called with some
option which would cause a given message to be returned as an error but with
user-definable text making up the body of the message, say:

exim -Xx 12345-67890-00 "Your message contains a virus and has been rejected."

Is there such an option?
--
Mike Kenyon <mike@???> | Tel: +44 (0) 1902 376351
I.T. Manager for David Austin Roses Ltd | Fax: +44 (0) 1902 372142