[Exim] Phreezing and Queuing

Exim-Users

How do I intercept a message and deny it from being delivered to the remote
server.
For e.g.. if I have a 9Meg e-mail sitting in my spool dir. and I want to
deny that message from going out - is there any way I can get that message
send back to the sender and have exim deliver like a note to the user saying
it was rejected.

Also How do I freeze a specific message, and how do I thaw it again?

Thanx

Marius Vincent
Technical
ELCB Information Services