Could you please share what method you used to migrate the data?

Also what is your observation on followings:

1. webmail & Carbonio Mail APP
2. 3rd-party client for desktop (i.e. outlook, thunderbird etc) and 3rd-party client for mobile (i.e. native gmail app, k9 etc.)

It is recommended to use supported platforms (i.e supported browser, native app) to get the best experience for carbonio CE.

Regards,

I recently migrated 114 mailboxes from a legacy Zimbra server to Carbonio (Zextras). While the migration seemed successful and all emails are visible in the Carbonio Webmail, we are facing a critical issue with IMAP clients (Thunderbird, K9 Mail).

The Problem: IMAP clients only see/sync emails up to the migration date. Any new emails arriving after the migration are visible in Webmail but are NOT fetched by IMAP clients.

Environment:

• Carbonio CE (latest)

• Clients: Thunderbird on Windows Server 2016 (Terminal Server), K9 Mail on Android.

• Migration path: Zimbra TGZ export/import.

What we have tried so far:

1. Reindexing: Ran zmprov reIndexMailbox user@domain.com start. No change for IMAP clients.

2. Manual UID Bump: If we create a temporary folder, move messages there and then back to Inbox, the IMAP client "wakes up" and sees the messages because they received new UIDs.

3. New Profile: Creating a completely new IMAP profile in K9 Mail still shows only old messages (pre-migration).

Observation: It seems that the UIDNEXT or MODSEQ values are somehow inconsistent or the IMAP index is corrupted in a way that doesn't trigger a sync for new items.

My Question: Is there a more efficient way to "reset" or "restart" the IMAP UID sequence (UIDVALIDITY/UIDNEXT) for a mailbox or a specific folder without manually moving thousands of messages back and forth? With 114 users and some mailboxes having 70k+ messages, the manual "move" method is extremely slow.

Is there any CLI command or database script to force a regeneration of the IMAP index/UIDs for a given account?

Thank you for any advice!