# Cyrus IMAP 3.12.0-rc1 Release Notes

Download from GitHub:

- https://github.com/cyrusimap/cyrus-imapd/releases/download/cyrus-imapd-3.12.0-rc1/cyrus-imapd-3.12.0-rc1.tar.gz

- https://github.com/cyrusimap/cyrus-imapd/releases/download/cyrus-imapd-3.12.0-rc1/cyrus-imapd-3.12.0-rc1.tar.gz.sig

## Major changes since the 3.10 series

- Add `allowspecialusesubfolder` imapd.conf(5) option to permit special-use subfolders. Thanks Michael Menge.

- Suppress duplicate calendar alarms in calalarmd.

- Add `caldav_alarm_suppress_file` imapd.conf(5) option to specify a file whose existence suppresses calalarmd processing

- Add `caldav_alarm_db_path` imapd.conf(5) option

- Add `caldav_alarm_support_components` imapd.conf(5) option to suppress alarms for all but select iCalendar component types.

- Added `--clearmodseq` option to ctl_conversationsdb(8)

- Optional I/O throttling, for testing

- The `DAV:principal-property-search` REPORT honours the previously set `DAV:displayname` property on matches. Thanks Дилян Палаузов.

- Adds `fatals_abort` imapd.conf(5) option for fatal errors to abort and produce a core dump.

- The CalDAV and CardDAV HTML administration pages allow editing the `DAV:displayname` and `description` properties. For calendars also the `color` and `order` properties. Thanks Дилян Палаузов.

- Enables the calendar-timezone-id (RFC 7809) DAV property even if tzdist http module is disabled.

- Adds support for IMAP JMAPACCESS (RFC 9698).

- Adds the mboxgroups authorization mechanism for access control groups that are managed within Cyrus.

- Adds support for IMAP PARTIAL (RFC 9394) and INPROGRESS (RFC 9585) extensions

- The IMAP parser now supports full 32-bit unsigned numbers

- Adds support for IMAP UTF8=ACCEPT (RFC 6855). This extension will only be advertised and supported if BOTH `reject8bit` and `munge8bit` imapd.conf(5) options are disabled

- User-defined flags are now replicated even when not in use on any messages.

- Adds support for the HAProxy protocol. The imapd(8), pop3d(8), lmtpd(8), nntpd(8), httpd(8), and timsieved(8) service daemons now accept a `-H` argument to enable this.

- Adds support for `comparator-i;unicode-casemap` (RFC 5051) to Sieve

- Running processes can now have debug logging toggled on/off by sending them SIGUSR1

- Updates the email address parser to preserve non-ASCII characters in the domain part. To apply this to existing messages, reconstruct(8) the mailboxes with the `-G` option to force reparsing email headers.

- master(8) now restarts failing DAEMON processes, and SERVICE processes with the `babysit` flag, forever, with a short delay in case of recurring failures. Previously, such processes that failed too many times in a short space of time were disabled until the operator sent a SIGHUP.

- Increased granularity of Prometheus report frequency configuration.

- Adds JMAP Email/query filter conditions `messageId`, `references`, and `inReplyTo`. See New JMAP Email/query filter conditions.

- Add a `skipuser-$userid` touchfile to sync directories. See sync_client(8).

- Adds `replicaonly` imapd.conf(5) config option to mark a server as being only a replica, blocking non-silent writes, and deactivating calalarmd(8) processing.

## Removed features

The following features and behaviours have been removed in 3.12. If your deployment depends on these, you should not upgrade to 3.12.

- The experimental Cyrus Backups feature has been removed.

- DIGEST-MD5 and NTLM are no longer supported in httpd. You may need to remove DIGEST-MD5 from `sasl_mech_list` in imapd.conf(5). Thanks Дилян Палаузов.

- The `improved_mboxlist_sort` imapd.conf(5) option had no effect since v3.6. It is now deprecated. Thanks Дилян Палаузов.

- timsieved(8) now always sends a capability response after a successful authentication, per RFC 5804. The `sieve_sasl_send_unsolicited_capability` imapd.conf(5) option is now deprecated. Thanks Дилян Палаузов.

- Support for the legacy IMAP XMOVE command has been removed.

- Removed Kerberos 4 support. Thanks Дилян Палаузов.

- Removed MIT Kerberized POP3 support. Thanks Дилян Палаузов.

## Storage changes

- None so far

## Updates to default configuration

The cyr_info(8) conf, conf-all and conf-default subcommands accept an -s <version> argument to highlight imapd.conf(5) options that are new or whose behaviour has changed since the specified version. We recommend using this when evaluating a new Cyrus version to check which configuration options you will need to examine and maybe set or change during the process.

- The `maxlogins_per_user` and `maxlogins_per_host` imapd.conf(5) options now apply per service, not globally. So for example if you have `maxlogins_per_user: 5` and some user has 5 active IMAP sessions, the user will still be able to access HTTP services.

  The LMTP service now uses these limits too. This can prevent resource starvation when a lot of mail is being delivered to a mailbox that is locked for a long time. Instead of having many lmtpd(8) processes waiting on the lock, excess connections attempting delivery to the same mailbox will be deferred with a 4xx response.

- The `prometheus_update_freq` imapd.conf(5) option has been deprecated and replaced by `prometheus_service_update_freq`, `prometheus_master_update_freq`, and `prometheus_usage_update_freq`, allowing these sets of statistics to be reported at different frequencies. The relatively-expensive usage statistics are no longer reported by default. To re-enable, configure a suitable update frequency for `prometheus_usage_update_freq`.

## Security fixes

- Fixed Issue #5046: prevent Cyrus IMAP servers being used in Application Layer Protocol Confusion (ALPACA) attacks, particularly against web browsers

## Significant bugfixes

- Fixed Issue #1763: Adds a way to freeze an entire server temporarily while taking snapshots or similar, using cyr_withlock_run(8). This relies on a new `global_lock` imapd.conf(5) option being enabled, which is enabled by default. Whether or not this setting is enabled, you can also use `cyr_withlock_run --user` to run a command with a single user locked.

- Fixed Issue #5146: can't subscribe to shared mailbox when username is a prefix of owner's username

  Subscriptions databases will be upgraded the next time they're opened, and any bad entries due to the bug will be found and fixed. You can force this for a particular user by connecting to IMAP as them and issuing a command like `. LSUB "" "*"` or similar, but this will happen anyway during normal usage.

- Fixed Issue #4797: all man pages are now always built and installed

- Fixed Issue #5309: deadlock on shutdown (thanks Mark Cammidge)

- Fixed Issue #5380: expunge only did one message at a time