2023-07-16    CYRUS IMAP SYSADMINS BEWARE, DEBIAN BOOKWORM
                          MIGHT HOSE YOUR MAIL


A warning for all sysadmin using Cyrus imap on Debian Bullseye, don't
switch to Debian Bookworm just yet. Your users might lose access to
their email. (Updated on 2023-07-19)

You will want to carefully investigate Debian Bug 1037346[1].

Update - the bugreport now includes a remark from the packagers:
,----
| the patch needed to update to 3.6 is included in Debian version 
| 3.2.6-2+deb11u2.
`----


For those that have already switched: read (and then do) this[2].

You also want to read the Cyrus manual on the recommended way to
upgrade, here.[3]

AFAICT, this shows that you can not use Debian bullseye-backports
either.

You might be able to avoid problems by selecting the right version from
Debian Snapshot[4].


[1]: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1037346

[2]: https://github.com/jaymzh/recover-cyrus/blob/main/README.md

[3]: https://www.cyrusimap.org/3.6/imap/download/upgrade.html#versions-to-upgrade-from

[4]: http://snapshot.debian.org/binary/cyrus-imapd/