Cyrus IMAP 3.6.0-rc2 Release Notes

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Major changes since the 3.4 series

  • All members of a newly created mailbox hierarchy will now be selectable mailboxes. In other words, when creating mailbox, both and will also be created as real mailboxes.

  • XFER will no longer move individual mailboxes that would leave unselectable mailboxes behind in the user heirarchy.

  • Update IMAP PREVIEW extension from draft-ietf-extra-imap-fetch-preview-07 to RFC 8970.

  • JMAP Blob handling updated to draft-ietf-jmap-blob-04

  • Always return ‘blobId’ and ‘size’ in Contact/setcreate, Contact/setupdate, and Contact/get responses.

  • Added Bearer authentication for RFC 7519 JSON Web Tokens. See http_jwt_key and http_jwt_max_age in imapd.conf(5).

  • Added icalendar_max_size and vcard_max_size imapd.conf(5) options to limit the size of iCalendar and vCard resources that can be stored.

  • Added caldav_accept_invalid_rrules imapd.conf(5) option to configure whether invalid RRULES should be accepted or rejected. They were previously always rejected.

  • The event_extra_params imapd.conf(5) option now supports a vnd.fastmail.jmapEmail selector, which adds a JMAP Email object to event messages. If you enable this selector, you might consider removing vnd.cmu.envelope, vnd.cmu.emailid, and vnd.cmu.threadid, as they would be redundant.

  • Added search_maxsize imapd.conf(5) option to limit how much of long message body parts are indexed by Xapian, which can improve indexing and snippet-generation latency. The default is 4MB. An earlier implementation applied a hardcoded 4MB limit to entire messages; systems that had this implementation may notice an increase in index size due to more text now being indexed.

  • The squatter(8) -s delta option now requires the delta argument.

  • Added an upper limit to sync_client(8)’s exponential reconnect backoff, configurable with the sync_reconnect_maxwait imapd.conf(5) option.

  • sync_client(8) now recognises when the remote sync_server(8) has been shut down cleanly, and doesn’t log a bunch of disconnection errors about it.

  • sync_client(8) -A mode now keeps processing subsequent mailboxes after errors (reconnecting to the replica if necessary), instead of bailing out at the first error. This means everything that can be replicated is replicated.

  • New sync_client(8) -N option to skip users that are currently being replicated by another process, rather than blocking on the lock only to have nothing left to do once it’s been obtained.

  • Added an inactivity timeout for WebSocket connections, configurable with the websocket_timeout imapd.conf(5) option.

  • Mailboxes and user metadata directories are now organised on disk by UUID rather than by mailbox name. See Storage changes below.

  • Sieve scripts are now stored in a special mailbox, rather than in sievedir. Compiled bytecode is still stored in sievedir. The name of the mailbox can be overridden with the sieve_folder imapd.conf(5) option (default: ‘#sieve’).

  • Experimental processimip Sieve action, for updating calendar entries based on iMIP (RFC 6047) messages.

  • Support for JMAP Push (RFC 8620) over EventSource, with polling interval controlled by the jmap_pushpoll imapd.conf(5) option (default: 60s).

  • Experimental support for JMAP Push over WebSockets, if Cyrus has been compiled with WebSockets enabled. Controlled by the same jmap_pushpoll option.

  • When a MIME part Content-Type header incorrectly specifies multiple charsets, Cyrus now checks each charset for validity and uses the last valid one. Previously, it would just use the first one, which is often junk when multiple are present.

  • JMAP Email/query and XCONV IMAP extension commands no longer ignore the SEEN state of messages in the “Trash” mailbox when evaluating conversation flags. Queries must explicitly exclude the “Trash” mailbox to ignore SEEN state of messages in “Trash”.

  • JMAP Contact.importance property is now a per-user property rather than shared.

  • JMAP Contacts now uses Apple-style labels on vCard ADR/TEL/EMAIL properties (via property grouping)

  • JMAP Contacts avatars can now reference any valid blob, not only blobs originally uploaded via JMAP.

  • Preliminary support for building with OpenSSL 3.

Storage changes


Please consult Upgrading to 3.6 prior to upgrading.

Mailboxes and user metadata directories are now organised on disk by UUID rather than by mailbox name.

At startup (or when you run ctl_cyrusdb -r manually), ctl_cyrusdb(8) will upgrade mailboxes.db to accommodate both old-style and new-style storage.

By default, new top-level mailboxes will be created in the new style. Mailboxes that already exist will remain in the old style until you convert them with relocate_by_id(8). New mailboxes below the top level will be created in the same style as their parent mailbox.

The new cyr_ls(8) tool can be used to examine the on-disk contents of a given mailbox name. mbpath(8) can be used to find where on disk a given mailbox and its metadata are.

If you want new top level mailboxes to be created in the old style, you can enable the mailbox_legacy_dirs imapd.conf(5) option, which defaults to off. With this turned on, you may still use relocate_by_id to convert them to the new style.

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 reverseuniqueids imapd.conf(5) option is now deprecated and unused. Reverse UNIQUEID records are now standard and cannot be turned off.

Security fixes

  • None so far

Significant bugfixes

  • Fixed Issue #3325: email addresses with quoted-string names were stored in the cache and search indexes without quotes, which could cause inconsistencies in handling. Affected mailboxes can be fixed by first running reconstruct(8) to repair the cache, and then squatter(8) to reindex the mailbox.

  • Fixed Issue #3421: PROPFIND <C:schedule-calendar-transp> now returns an XML element instead of text (thanks Дилян Палаузов)

  • Fixed Issue #3896: the -d (dump) and -u (undump) options to ctl_mboxlist(8) now correctly dump and undump all fields in mailboxes.db entries. The intermediary file format is now JSON. This change makes it possible to follow the procedure for switching improved_mboxlist_sort described in Enabling improved_mboxlist_sort.

  • Fixed Issue #4035: ctl_cyrusdb -r now recovers from mailboxes.db records with missing uniqueids, instead of crashing. A new -P option to reconstruct(8) enables repairing mailboxes whose header files are missing uniqueids.