--- Comment #5 from Simon Arlott <bugzilla.exim.simon@???> 2010-05-19 20:10:48 ---
(In reply to comment #4) > As this is a local delivery if the delay function returned immediately it would
> be possible to have two deliveries occur before the generated ID changed.
I can't reproduce this issue with a test program, so I suggest you add the
following configuration option:
log_selector = +pid
This will confirm whether or not the same Exim pid is reusing the message ID
for a second message. Could you reverse the order of the recipients to trigger
the issue and test it with the pid logged?