Exchange blocking duplicate messages?

[Hirsh, Joshua]

 Modifying the Message-ID field even slightly would do the trick. I'm not
too sure how tricky this will be depending on which MTA is in use though.

 In my case, I quarantine the entire message as a queue file and just dump
it back into the queue directly if the user requests it. So in the end, the
user gets the original message without the attachments and the note saying
why they were removed, then when it's released the message goes through
again with the attachments using the same Message-ID.

 Do you think it's feasible to slightly modify the Message-ID on the first
message when the attachments are removed, but keep it intact for the saved
queue file?


 I've noticed that it seems to be a time based filter on Exchange. If I
release the message right away, they never get it. If I wait a few hours
then release it, it always goes through. Exchange must keep a table of the
past x amount of Message-ID's it sees coming in.


 Thanks,
-Joshua