Non-destructive deduplication

[Tristan Miller]

Greetings.

I use Dovecot 2.2.29.1 as my IMAP server.  Owing to a bug in my mail
client [1], several unique messages (mostly in my Sent folder) have
duplicate Message-ID headers.  Dovecot itself doesn't seem to be
bothered by this, though my mail client is confused by the false
duplicates.  (It screws up the threading display, and results in data
loss when I run the client's deduplication filter.)

I would like to change the Message-ID headers in the "duplicate" message
files stored in my IMAP server so that they are unique.  I realize that
this has disadvantages of its own, but I can't think of a better
alternative.

So this leads me to two questions:

1) Will Dovecot get confused if I simply open the message files in a
text editor and manually change their Message-ID headers?  If so, how
should I go about changing the Message-ID headers?

2) Does there exist any tool that will scan a maildir folder to find
messages with duplicate Message-IDs, and automatically rewrite the
Message-ID headers so that they are (probably) unique?  I could
probably kludge together a quick shell script, but if someone's already
gone to the trouble of writing such a tool and making it relatively
robust, I'd rather use that instead.

Regards,
Tristan

[1]
http://www.thewildbeast.co.uk/claws-mail/bugzilla/show_bug.cgi?id=3828

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
                  Tristan Miller
Free Software developer, ferret herder, logologist
             https://logological.org/
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <http://dovecot.org/pipermail/dovecot/attachments/20170610/b3dbc893/attachment.sig>