I have just spent ~4hrs trying to recover 155 users. According to the debian changelog (see e.g. https://sources.debian.org/patches/cyrus-imapd/3.2.6-2+deb11u2/ , last entry) the package should have the patches required for a transition to 3.6. Luckily I could "recover" by downgrading to 3.2 again.
So i have:
- UniqeId in mailbox.db and cyrus.header
- MinorVersion of 12
- all mails have GUID != 0
- No error or crash runing ctl_cyrusdb -r on 3.6
And yet, after the upgrade to 3.6 the mailboxes from 3.2 seem to live a separate life in mailboxes.db. 3.6 does not recognize them, I cannot use reconstruct -P because there are no mailbox-ids attached to the mailboxes.
