Re: korgalore delivering duplicates

[Konstantin Ryabitsev <mricon@kernel.org>]

On Tue, Jan 27, 2026 at 07:18:18PM +0100, Ard Biesheuvel wrote:
> - messages received directly that are also pulled by korgalore, potentially
>   multiple times if they were cross-posted to multiple mailing lists;
> - outgoing messages that are cc'ed to multiple mailing lists, which are then
>   looped back and delivered by korgalore in the same manner.

Okay, for JMAP and IMAP targets, korgalore now checks if a message with the
same Message-ID already exists in the target folder before attempting to
import it. This uses JMAP's Email/query with a header filter for JMAP targets,
and IMAP's SEARCH HEADER for IMAP targets. Gmail already deduplicates
automatically via its API, so no changes were needed there.

Not doing anything for Maildir targets for now, because I don't want to
iterate through potentially thousands of messages.

I've also added an X-Korgalore-Trace header to all delivered messages, e.g.:

    X-Korgalore-Trace: from feed=lei:myquery for delivery=fastmail
      by korgalore/0.5-dev; Mon, 27 Jan 2026 17:10:09 -0500

This should help you identify which messages came through korgalore and
from which feed, at least.

The changes are in the 0.5 master branch and need more testing, if you are
able to do that via the git repo directly.

Best wishes,
-K