[BUG] GMail IMAP download not finding new emails

[cliebBS]

Version

2.0.0

Steps to Reproduce

Upgrade a working Bichon 1.6.4 instance to Bichon 2.0.0, then observe that emails from GMail are no longer downloaded.

Issue Description

I have a folder in GMail that I've been archiving emails from since pre-1.0. Since upgrading to Bichon 2.0.0 yesterday, I noticed that every time the download runs, it finds no new emails even though there have been probably 1000 emails added to that folder since the most recently download message.

I tried manually triggering a download with backfill and see this in my logs:

bichon  | 2026-08-06T18:13:15.204+00:00  INFO bichon_core::imap::executor: fetch_new_mail_range: UID SEARCH result account_id=441285114957880 mailbox=portal_issues start_uid=816098 found=1 first=816117 last=816117
bichon  | 2026-08-06T18:13:17.042+00:00  INFO bichon_core::cache::imap::download::flow: reconcile: computed highest_uid for mailbox account_id=441285114957880 mailbox=portal_issues local_highest=816097 new_highest=816117
bichon  | 2026-08-06T18:13:17.042+00:00  INFO bichon_core::cache::imap::download::flow: reconcile: persisting mailbox state account_id=441285114957880 mailbox=portal_issues highest_uid=816117

Here is the configuration I have for this account:

ID: 441285114957880
Email: clieb@example.com
Name: clieb@example.com
Enabled: yes
Download Interval (minutes): every 60 minutes
Download batch size: 30
Max email size: Default: 100 MB
Capabilities:
NAMESPACE, X-GM-EXT-1, UTF8=ACCEPT, ENABLE, LIST-EXTENDED, IMAP4rev1, UIDPLUS, COMPRESS=DEFLATE, CONDSTORE, IDLE, MOVE, LIST-STATUS, XLIST, LITERAL-, UNSELECT, ESEARCH, APPENDLIMIT=35651584, ID, SPECIAL-USE, CHILDREN, QUOTA
Download Strategy: Download All Emails
Cron Schedule: n/a

host: imap.gmail.com
port: 993
encryption: Ssl
Trust Any TLS Certificate: false
Auth: Password
use proxy: No Proxy

Screenshots or Logs (optional)

Attach any screenshots or logs if available.

[tiliarou]

Exactly the same issue with a yahoo mailbox : used it for initial sync (which failed in the middle) with bichon 1.x.x
Then upgraded to 2.0.0 and first manual sync I used backfill, which found all the missing emails from the failed initial sync (I need to confirm this point 100% though).
But now every scheduled sync doesn't fin any new email, it's broken. Manual sync without backfill is also filing to find and download new emails. I have to use backfill on a manual sync to actually download new emails...

[rustmailer]

I guess the issue came from the last change to UID SEARCH that fetches the UID list. I tried it in Zoho Mail and it worked fine. I've pushed some changes to the fix/imap-uid-search-truncation branch. Would you be willing to test whether this resolves the issue before I merge it into main?

[tiliarou]

I guess the issue came from the last change to UID SEARCH that fetches the UID list. I tried it in Zoho Mail and it worked fine. I've pushed some changes to the fix/imap-uid-search-truncation branch. Would you be willing to test whether this resolves the issue before I merge it into main?

yes I will try the branch

[tiliarou]

@rustmailer looks like you fixed it, I tried your new branch and it downloaded the missing new emails on a scheduled run. I will try a manual run as well (without backfill) to double check, now I got rate limited by yahoo server...

[rustmailer]

@tiliarou thanks, I'll merge to main and release 2.0.1 today.

[joy4eg]

I think that fix has introduced a new issue. Email duplication.
I.e. Email was received in INBOX and saved to the DB, then I deleted that email using the web UI or email client, which moved it into TRASH where app picked it up again :)