Message-IDs in Sent Items folder from Exchange

[David Base]

We've recently migrated mail from Exchange to Cyrus IMAP.  All went well
(I think, so far), except messages moved from the Exchange Sent Items
folders don't have Message-IDs in their headers.  The problem is that
our sort-of-custom java mail imap client needs to see Message-IDs.  I'm
toying with the idea of writing a script that inserts unique MessageIDs
in the headers of the Sent Items messages that don't have them, but I'm
wondering what effect this might have on the cyrus.cache, cyrus.headers,
and cyrus.index file in the Sent Items directories.  Anyone know if this
is do-able?  Would I then have to reconstruct the user/username/Sent
Items directories?

Thanks,
Dave Base
---
Cyrus Home Page: http://asg.web.cmu.edu/cyrus
Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html