imapd.conf

IMAP configuration file

DESCRIPTION

/etc/imapd.conf is the configuration file for the Cyrus IMAP server. It defines local parameters for IMAP.

Each line of the /etc/imapd.conf file has the form option: value

where option is the name of the configuration option being set and value is the value that the configuration option is being set to.

Although there is no limit to the length of a line, a ``\'' (backslash) character may be used as the last character on a line to force it to continue on the next one. No additional whitespace is inserted before or after the ``\''. Note that a line that is split using ``\'' character(s) is still considered a single line.

For example option:\

value1 value2 \

value3

is equivalent to option: value1 value2 value3

Blank lines and lines beginning with ``#'' are ignored.

For boolean and enumerated options, the values ``yes'', ``on'', ``t'', ``true'' and ``1'' turn the option on, the values ``no'', ``off'', ``f'', ``false'' and ``0'' turn the option off.

Duration options take the form of a number followed by a unit, for example 32m (32 minutes). Units are d (days), h (hours), m (minutes) and s (seconds). Multiple units can be combined and will be summed together, for example 1h30m is equivalent to 90m. If no unit is specified, an option-specific backward-compatible default unit is assumed (documented on an option-by-option basis). These are simple time units: 1d=24h, 1h=60m, 1m=60s (daylight savings, timezones, leap adjustments, etc are not considered).

Byte size options take the form of a number followed by a unit, for example 1KiB (1 kibibyte). Units are B (bytes), KiB (kibibytes), MiB (mebibytes), and GiB (gibibytes), which may also be spelt KB, MB, and GB. Units are parsed without regard to case. Note that regardless of spelling, these units are always powers of 2, and never metric. That is, 1GiB = 1024MiB, 1MiB = 1024KiB, 1KiB = 1024B. If no unit is specified, an option-specific backward-compatible default unit is assumed (documented on an option-by-option basis).

OPTION DESCRIPTIONS

The sections below detail options that can be placed in the /etc/imapd.conf file, and show each option's default value. Some options have no default value, these are listed with ``<no default>''. Some options default to the empty string, these are listed with ``<none>''.

@include

Default: <none>

Directive which includes the specified file as part of the configuration. If the path to the file is not absolute, CYRUS_PATH is prepended.

acl_admin_implies_write

Default: 0

If enabled, any user with the admin ACL on a mailbox implicitly gets the ability to write to that mailbox as well.

addressbookprefix

Default: #addressbooks

The prefix for the addressbook mailboxes hierarchies. The hierarchy delimiter will be automatically appended. The public addressbook hierarchy will be at the toplevel of the shared namespace. A user's personal addressbook hierarchy will be a child of their Inbox.

admins

Default: <empty string>

Default: 1

Allow use of the POP3 APOP authentication command.

Note that this command requires that SASL is compiled with APOP support, that the plaintext passwords are available in a SASL auxprop backend (e.g., sasldb), and that the system can provide enough entropy (e.g., from /dev/urandom) to create a challenge in the banner.

Default: 1

Defaults to enabled. If disabled, disallows the use of the SETACL command at all via IMAP.

allowspecialusesubfolder

Default: <none>

The pathname of a callout to be used to automatically add annotations or flags to a message when it is appended to a mailbox. The path can be either an executable (including a script), or a UNIX domain socket.

annotation_callout_disable_append

Default: 0

Disables annotations on append with xrunannotator.

annotation_db

Default: twoskip

The cyrusdb backend to use for mailbox annotations.

Allowed values: skiplist, twom, twoskip

annotation_db_path

Default: <none>

The absolute path to the annotations db file. If not specified, will be configdirectory/annotations.db

annotation_definitions

Default: <none>

File containing external (third-party) annotation definitions.

Each line of the file specifies the properties of an annotation and has the following form:

name, scope, attrib-type, proxy-type, attrib-names, acl

name

is the hierarchical name as in RFC 5257 or RFC 5464 (in the latter case, without the leading /shared or /private). For example, /vendor/acme/blurdybloop.

scope

specifies whether the annotation is for the server, a mailbox, or a message.

attrib-type

specifies the attribute data type, which is used only to check the string value passed by clients when setting annotations. The attrib-type is one of:

string: any value is accepted.
content-type: this obsolete data type, which was useful for early drafts of the standard, is accepted but silently translated to string.
boolean: only the strings "true" or "false" are accepted. Checking is case-insensitive but the value is forced to lowercase.
int: integers are accepted.
uint: non-negative integers are accepted.

proxy-type

Default: unix

The authorization mechanism to use.

Allowed values: unix, pts, krb5, mboxgroups

autocreate_acl

Default: <none>

If folders are to be created by autocreate_inbox_folders, this setting can be used to apply additional ACLs to the autocreated folders. The syntax is "autocreate_acl folder identifier rights", where folder must match one of the autocreate_inbox_folders folders, identifier must be a valid cyrus identifier, and rights must be a valid cyrus rights string.

Multiple identifier|rights pairs can be assigned to a single folder by providing this setting multiple times.

For example, "autocreate_acl Plus anyone p" would allow lmtp delivery to a folder named "Plus".

autocreate_inbox_folders

Default: <none>

If a user does not have an INBOX already, and the INBOX is to be created, create the list of folders in this setting as well. autocreate_inbox_folders is a list of INBOX's subfolders separated by a "|", that are automatically created by the server under the following two scenarios. Leading and trailing whitespace is stripped, so "Junk | Trash" results in two folders: "Junk" and "Trash". See also the xlist-flag option, for setting special-use flags on autocreated folders.

INBOX folders are created under both the following conditions:

The user logins via the IMAP or the POP3 protocol. autocreate_quota option must have a value of zero or greater.
A message arrives for the user through the lmtpd(8). autocreate_post option must be enabled.

autocreate_post

Default: 0

If enabled, when lmtpd(8) receives an incoming mail for an INBOX that does not exist, then the INBOX is automatically created by lmtpd and delivery of the message continues.

autocreate_quota

Default: -1

If set to a value of zero or higher, users have their INBOX folders created upon a successful login event or upon lmtpd(8) message delivery if autocreate_post is enabled, provided their INBOX did not yet already exist.

The user's quota is set to the value if it is greater than zero, otherwise the user has unlimited quota.

Note that quota has kibibyte granularity. Values specified here will be truncated to the nearest whole kibibyte.

For backward compatibility, if no unit is specified, kibibytes is assumed.

autocreate_quota_messages

Default: -1

If set to a value of zero or higher, users who have their INBOX folders created upon a successful login event (see autocreate_quota), or upon lmtpd(8) message delivery if autocreate_post is enabled, receive the message quota configured in this option.

The default of -1 disables assigning message quota.

For consistency with autocreate_quota, a value of zero is treated as unlimited message quota, rather than a message quota of zero.

autocreate_sieve_compiled_script

Default: <none>

Deprecated in favour of autocreate_sieve_script_compiled.

autocreate_sieve_folders

Default: <none>

A "|" separated list of subfolders of INBOX that will be automatically created, if requested by a sieve filter, through the "fileinto" action. The default is to create no folders automatically.

Leading and trailing whitespace is stripped from each folder, so a setting of "Junk | Trash" will create two folders: "Junk" and "Trash".

autocreate_sieve_script

caldav_alarm_db_path

Default: <none>

Path to the caldav_alarm database file - defaults to $confdir/caldav_alarm.sqlite3 if not set

caldav_alarm_support_components

Default: VEVENT VTODO

Space-separated list of iCalendar component types for which calalarmd generates alarms.

Allowed values: VEVENT, VTODO

caldav_alarm_suppress_file

Default: <none>

If this file exists, calalarmd will not process events

caldav_allowattach

Default: 1

Enable managed attachments support on the CalDAV server.

caldav_allowcalendaradmin

Default: 0

Enable per-user calendar administration web UI on the CalDAV server.

caldav_allowscheduling

Default: on

Enable calendar scheduling operations. If set to "apple", the server will emulate Apple CalendarServer behavior as closely as possible.

Allowed values: off, on, apple

caldav_create_attach

Default: 1

Create the 'Attachments' collection if it doesn't already exist.

caldav_create_default

Default: 1

Create the 'Default' calendar if it doesn't already exist.

caldav_create_sched

Default: 1

Create the 'Inbox' and 'Outbox' calendars if they don't already exist.

caldav_historical_age

Default: 7d

How long after an occurrence of event or task has concluded that it is considered 'historical'. Changes to historical occurrences of events or tasks WILL NOT have invite or reply messages sent for them. A negative value means that events and tasks are NEVER considered historical.

For backward compatibility, if no unit is specified, days is assumed.

caldav_maxdatetime

Default: 20380119T031407Z

The latest date and time accepted by the server (ISO format). This value is also used for expanding non-terminating recurrence rules.

Note that increasing this value will require the DAV databases for calendars to be reconstructed with the dav_reconstruct(1) utility in order to see its effect on serer-side time-based queries.

caldav_mindatetime

Default: 19011213T204552Z

The earliest date and time accepted by the server (ISO format).

caldav_realm

Default: <none>

The realm to present for HTTP authentication of CalDAV resources. If not set (the default), the value of the servername option will be used.

calendar_component_set

Default: VEVENT VTODO VJOURNAL VFREEBUSY VAVAILABILITY VPOLL

Space-separated list of iCalendar component types that calendar object resources may contain in a calendar collection. This restriction is only set at calendar creation time and only if the CalDAV client hasn't specified a restriction in the creation request.

Allowed values: VEVENT, VTODO, VJOURNAL, VFREEBUSY, VAVAILABILITY, VPOLL

calendar_default_displayname

Default: personal

The displayname to be used when creating a user's 'Default' calendar.

calendar_minimum_alarm_interval

Default: 5m

The minimum allowed interval between alarms for a recurring event. Primarily used to suppress alarms for MINUTELY and SECONDLY recurrences. The minimum value is 0, which will allow all alarms.

For backward compatibility, if no unit is specified, minutes is assumed.

calendar_suppress_duplicate_alarms

Default: 1

Suppress duplicate calendar alarms in calalarmd. If this is set, then at most one alarm notification is sent for any given alarm action, point in time and calendar event.

calendar_user_address_set

Default: <none>

Space-separated list of domains corresponding to calendar user addresses for which the server is responsible. If not set (the default), the value of the defaultdomain option will be used.

calendarprefix

Default: #calendars

The prefix for the calendar mailboxes hierarchies. The hierarchy delimiter will be automatically appended. The public calendar hierarchy will be at the toplevel of the shared namespace. A user's personal calendar hierarchy will be a child of their Inbox.

carddav_allowaddmember

Default: 0

Enable support for POST add-member on the CardDAV server.

conversations_expire_after

cyrusdb_autoconvert

Default: 0

Automatically convert any existing db to the configured engine for that database if possible.

dav_lock_timeout

Default: 20s

The maximum time to wait for a write lock on the per-user DAV database before timeout. For HTTP requests, the HTTP status code 503 is returned if the lock can not be obtained within this time.

If no unit is specified, seconds is assumed.

dav_realm

Default: <none>

The realm to present for HTTP authentication of generic DAV resources (principals). If not set (the default), the value of the servername option will be used.

davdriveprefix

Default: #drive

The prefix for the DAV storage mailboxes hierarchies. The hierarchy delimiter will be automatically appended. The public storage hierarchy will be at the toplevel of the shared namespace. A user's personal storage hierarchy will be a child of their Inbox.

davnotificationsprefix

Default: #notifications

The prefix for the DAV notifications hierarchy. The hierarchy delimiter will be automatically appended. The public notifications hierarchy will be at the toplevel of the shared namespace. A user's personal notifications hierarchy will be a child of their Inbox.

debug

Default: 0

If enabled, allow syslog() to pass LOG_DEBUG messages.

This can be toggled for a running process by sending it SIGUSR1.

debug_command

Default: <none>

Debug command to be used by processes started with -D option. The string is a C format string that gets 3 options: the first is the name of the executable (as specified in the cmd parameter in cyrus.conf). The second is the pid (integer) and the third is the service ID.

Example: /usr/local/bin/gdb /usr/cyrus/bin/%s %d

debug_log_sync_partition_choice

Default: 0

If enabled, replication will log which partition it chose for staging. This is mainly useful for regression testing the sync_client -a switch.

debug_slowio

Default: 0

If enabled, I/O operations will be artificially slowed down. This option has no effect unless Cyrus was compiled with the --enable-debug-slowio configure argument. This is mainly useful for testing certain edge case handling.

debug_writefail_guid

Default: <none>

If set, any arriving message with this guid will fail as if the underlying disk write had failed, pretending to be a disk full condition. This is mainly useful for regression testing certain edge case handling. Currently only implemented for replication uploads.

defaultacl

Default: anyone lrs

The Access Control List (ACL) placed on a newly-created (non-user) mailbox that does not have a parent mailbox.

defaultdomain

Default: internal

The default domain for virtual domain support.

defaultpartition

Default: <none>

The partition name used by default for new mailboxes. If not specified, the partition with the most free space will be used for new mailboxes.

Note that the partition specified by this option must also be specified as partition-name, where you substitute 'name' for the alphanumeric string you set defaultpartition to.

defaultsearchtier

Default: <empty string>

Name of the default tier that messages will be indexed to. Search indexes can be organized in tiers to allow index storage in different directories and physical media. See squatter(8) for details. The default search tier also requires the definition of an according searchpartition-name entry.

This option MUST be specified for xapian search.

defaultserver

Default: <none>

The backend server name used by default for new mailboxes. If not specified, the server with the most free space will be used for new mailboxes.

delete_mode

Default: delayed

The manner in which mailboxes are deleted. In the default delayed mode, mailboxes that are being deleted are renamed to a special mailbox hierarchy under the deletedprefix, to be removed later by cyr_expire(8).

In immediate mode, the mailbox is removed from the filesystem immediately.

Allowed values: immediate, delayed

delete_unsubscribe

Default: 0

Whether to also unsubscribe from mailboxes when they are deleted. Note that this behaviour contravenes RFC 3501 section 6.3.9, but may be useful for avoiding user/client software confusion.

deletedprefix

Default: DELETED

duplicate_db_path

Default: <none>

The absolute path to the duplicate db file. If not specified, will be configdirectory/deliver.db

duplicatesuppression

Default: 1

If enabled, lmtpd will suppress delivery of a message to a mailbox if a message with the same message-id (or resent-message-id) is recorded as having already been delivered to the mailbox. Records the mailbox and message-id/resent-message-id of all successful deliveries.

event_content_inclusion_mode

Default: standard

The mode in which message content may be included with MessageAppend and MessageNew. "standard" mode is the default behavior in which message is included up to a size with the notification. In "message" mode, the message is included and may be truncated to a size. In "header" mode, it includes headers truncated to a size. In "body" mode, it includes body truncated to a size. In "headerbody" mode, it includes full headers and body truncated to a size.

Allowed values: standard, message, header, body, headerbody

event_content_size

Default: 0

Truncate the message content that may be included with MessageAppend and MessageNew. Set 0 to include the entire message itself.

If no unit is specified, bytes is assumed.

event_exclude_flags

Default: <none>

Don't send event notification for given IMAP flag(s).

event_exclude_specialuse

Default: \Junk

Don't send event notification for folder with given special-use attributes. Set ALL for any folder.

event_extra_params

Default: timestamp

Space-separated list of extra parameters to add to any appropriated event.

Allowed values: bodyStructure, clientAddress, diskUsed, flagNames, messageContent, messageSize, messages, modseq, service, timestamp, uidnext, vnd.cmu.midset, vnd.cmu.unseenMessages, vnd.cmu.envelope, vnd.cmu.sessionId, vnd.cmu.mailboxACL, vnd.cmu.mbtype, vnd.cmu.davFilename, vnd.cmu.davUid, vnd.fastmail.clientId, vnd.fastmail.sessionId, vnd.fastmail.convExists, vnd.fastmail.convUnseen, vnd.fastmail.cid, vnd.fastmail.counters, vnd.fastmail.jmapEmail, vnd.fastmail.jmapStates, vnd.cmu.emailid, vnd.cmu.threadid, vnd.cmu.visibleUsers, vnd.fastmail.traceId

event_groups

Default: message mailbox

Space-separated list of groups of related events to turn on notification.

Allowed values: message, quota, flags, access, mailbox, subscription, calendar, applepushservice, jmap

event_notifier

Default: <none>

notifyd(8) method to use for "EVENT" notifications which are based on the RFC 5423. If not set, "EVENT" notifications are disabled.

expire_by_savedate

Default: 0

If true, calculate age of messages for expiry by the savedate (timestamp when the message was added to this folder) rather than gmtime (date header on the message). Default is true.

expire_keep_flagged

Default: 0

If true, don't expire messages which have the `Flagged` IMAP flag set. Default is false.

expunge_mode

Default: delayed

The mode in which messages (and their corresponding cache entries) are expunged. "semidelayed" mode is the old behavior in which the message files are purged at the time of the EXPUNGE, but index and cache records are retained to facilitate QRESYNC. In "delayed" mode, which is the default since Cyrus 2.5.0, the message files are also retained, allowing unexpunge to rescue them. In "immediate" mode, both the message files and the index records are removed as soon as possible. In all cases, nothing will be finally purged until all other processes have closed the mailbox to ensure they never see data disappear under them. In "semidelayed" or "delayed" mode, a later run of "cyr_expire" will clean out the retained records (and possibly message files). This reduces the amount of I/O that takes place at the time of EXPUNGE and should result in greater responsiveness for the client, especially when expunging a large number of messages.

Allowed values: immediate, semidelayed, delayed

failedloginpause

Default: 3s

Time to pause after a failed login.

If no unit is specified, seconds is assumed.

fastmailsharing

Default: 0

If enabled, use FastMail style sharing (oldschool full server paths).

fatals_abort

Default: 0

If enabled, when fatal errors are detected, Cyrus will call abort() to produce a core dump, unless the error was due to a misbehaving client. This is useful if you have the ability to debug a core dump.

If not enabled (the default), the process will exit normally with an error code.

flushseenstate

Default: 1

Deprecated. No longer used.

foolstupidclients

Default: 0

If enabled, only list the personal namespace when a LIST "*" is performed (it changes the request to a LIST "INBOX*").

force_sasl_client_mech

Default: <none>

Force preference of a given SASL mechanism for client side operations (e.g. murder environments). This is separate from (and overridden by) the ability to use the <host shortname>_mechs option to set preferred mechanisms for a specific host.

fulldirhash

Default: 0

HMAC digest keys must be embedded between the lines "-----BEGIN HMAC KEY-----" and "-----END HMAC KEY-----", encoded in base64.

Any lines before or after a PEM key definition are ignored, empty lines are ignored anywhere in the file.

The JSON Web Token must be the value of the HTTP "Authorization" header, using the "Bearer" authentication scheme. The JWS Header must include the "alg" and "typ" parameter. A header with any other parameter is rejected. The JWS Payload must include the "sub" claim with the Cyrus user identifier as value. It may include the "iat" claim (see http_jwt_max_age). A payload with any other claim is rejected.

http_jwt_max_age

Default: 0s

Defines the timespan in which a JSON Web Token is valid (see http_jwt_key_dir). The value must be zero or positive.

If non-zero, the timespan starts at the point in time specified in the "iat" claim of the JWS Payload and ends after the duration of this option value has passed. Tokens without an "iat" claim, or with an issue date in the future, are rejected. There is no leeway for clock skew. Starting from Cyrus version 3.8, the "iat" claim only is validated if no "exp" claim is present.

The zero value disables validation of the "iat" JWS claim.

Starting from Cyrus 3.8, the "nbf" and "exp" claims always are validated.

If no unit is specified, seconds is assumed.

httpallowcompress

Default: 1

If enabled, the server will compress response payloads if the client indicates that it can accept them. Note that the compressed data will appear in telemetry logs, leaving only the response headers as human-readable.

httpallowcors

Default: <none>

A wildmat pattern specifying a list of origin URIs ( scheme "://" host [ ":" port ] ) that are allowed to make Cross-Origin Resource Sharing (CORS) requests on the server. By default, CORS requests are disabled.

Note that the scheme and host should both be lowercase, the port should be omitted if using the default for the scheme (80 for http, 443 for https), and there should be no trailing '/' (e.g.: "http://www.example.com:8080", "https://example.org").

httpallowedurls

Default: <none>

Space-separated list of relative URLs (paths) rooted at httpdocroot to be served by httpd. If set, this option will limit served static content to only those paths specified (returning "404 Not Found" to any other client requested URLs). Otherwise, httpd will serve any content found in httpdocroot.

Note that any path specified by rss_feedlist_template is an exception to this rule.

httpallowtrace

Default: 0

Allow use of the TRACE method.

Note that sensitive data might be disclosed by the response.

httpcontentmd5

Default: 0

If enabled, HTTP responses will include a Content-MD5 header for the purpose of providing an end-to-end message integrity check (MIC) of the payload body. Note that enabling this option will use additional CPU to generate the MD5 digest, which may be ignored by clients anyways.

httpdocroot

Default: <none>

If set, http will serve the static content (html/text/jpeg/gif files, etc) rooted at this directory. Otherwise, httpd will not serve any static content.

httpkeepalive

Default: 20s

Set the length of the HTTP server's keepalive heartbeat. The default is 20 seconds. The minimum value is 0, which will disable the keepalive heartbeat. When enabled, if a request takes longer than httpkeepalive to process, the server will send the client provisional responses every httpkeepalive until the final response can be sent.

If no unit is specified, seconds is assumed.

httplogheaders

Default: <none>

Space-separated list of HTTP header fields that will be included in the requests logged by httpd(8).

httpmodules

Default: <empty string>

Space-separated list of HTTP modules that will be enabled in httpd(8). This option has no effect on modules that are disabled at compile time due to missing dependencies (e.g. libical).

Note that "domainkey" depends on "ischedule" being enabled, and that both "freebusy" and "ischedule" depend on "caldav" being enabled.

Allowed values: admin, caldav, carddav, cgi, domainkey, freebusy, ischedule, jmap, prometheus, rss, tzdist, webdav

httpprettytelemetry

Default: 0

If enabled, HTTP response payloads including server-generated markup languages (HTML, XML) will utilize line breaks and indentation to promote better human-readability in telemetry logs. Note that enabling this option will increase the amount of data sent across the wire.

httppts_uri

Default: <none>

The URL endpoint to use when for querying group membership, in URI Template (level 1) format [RFC 6570]. The URL MUST contain a variable called "groupId"

httptimeout

Default: 5m

Set the length of the HTTP server's inactivity autologout timer. The minimum value is 0, which will disable persistent connections.

For backward compatibility, if no unit is specified, minutes is assumed.

icalendar_max_size

Default: 0

Maximum allowed iCalendar size. CalDAV and JMAP will reject storage of resources whose iCalendar representation is larger than this.

If set to 0 (the default), a large internally-defined limit will be applied.

If no unit is specified, bytes is assumed.

idlesocket

Default: {configdirectory}/socket/idle

Unix domain socket that idled listens on.

ignorereference

Default: 0

For backwards compatibility with Cyrus 1.5.10 and earlier -- ignore the reference argument in LIST or LSUB commands.

imap_inprogress_interval

Default: 10s

The interval after which the server will send an "INPROGRESS" response code to the client during a long-running imap command (e.g. search, copy). The default is 10 seconds. The minimum value is 0, which will disable "INPROGRESS" response codes.

If no unit is specified, seconds is assumed.

imapidlepoll

Default: 60s

The interval for polling for mailbox changes and ALERTs while running the IDLE command. This option is used when idled is not enabled or cannot be contacted. The minimum value is 1 second. A value of 0 will disable IDLE.

If no unit is specified, seconds is assumed.

imapidletimeout

Deprecated. No longer used.

jmap_imagesize_annot

Default: <none>

The name of the per-message annotation, if any, that stores a JSON object, mapping message part numbers of MIME image types to an array of their image dimensions. The array must have at least two entries, where the first entry denotes the width and the second entry the height of the image. Any additional values are ignored.

For example, if message part 1.2 contains an image of width 300 and height 200, then the value of this annotation would be:

{ "1.2" : [ 300, 200 ] }

jmap_inlinedcids_annot

Default: <none>

The name of the per-message annotation, if any, that stores a JSON object, mapping RFC 2392 Content-IDs referenced in HTML bodies to the respective HTML body part number.

For example, if message part 1.2 contains HTML and references an inlined image at "cid:foo", then the value of this annotation would be:

{ "<foo>" : "1.2" }

Note that the Content-ID key must be URL-unescaped and enclosed in angular brackets, as defined in RFC 2392.

jmap_mail_max_size_attachments_per_email

Default: 10M

The value to return for the maxSizeAttachmentsPerEmail property of the JMAP "urn:ietf:params:jmap:mail" capabilities object. The Cyrus JMAP implementation does not enforce this size limit.

For backward compatibility, if no unit is specified, kibibytes is assumed.

jmap_max_calendareventnotifs

Default: 200

The maximum count of CalendarEventNotification objects to keep per account. Any notifications exceeding this count are expunged to make room for new ones. Zero or any negative number disables this limit.

jmap_max_calls_in_request

Default: 50

The maximum number of calls per JMAP request object. Returned as the maxCallsInRequest property value of the JMAP "urn:ietf:params:jmap:core" capabilities object.

jmap_max_catenate_items

Default: 100

The maximum number of items that can be catenated together by a JMAP Blob/upload action. Returned as the maxDataSources property value of the JMAP "urn:ietf:params:jmap:blob" capabilities object. Default value is 100.

jmap_max_concurrent_requests

Default: 5

The value to return for the maxConcurrentRequests property of the JMAP "urn:ietf:params:jmap:core" capabilities object. The Cyrus JMAP implementation does not enforce this rate-limit.

jmap_max_concurrent_upload

Default: 5

The value to return for the maxConcurrentUpload property of the JMAP "urn:ietf:params:jmap:core" capabilities object. The Cyrus JMAP implementation does not enforce this rate-limit.

jmap_max_delayed_send

Default: 512d

The value to return for the maxDelayedSend property of the JMAP "urn:ietf:params:jmap:emailsubmission" capabilities object. The Cyrus JMAP implementation does not enforce this limit.

If no unit is specified, seconds is assumed.

jmap_max_objects_in_get

Default: 4096

The maximum number of ids that a JMAP client may request in a single "/get" type method call. The actual number of returned objects in the response may exceed this number if the JMAP object type supports unbounded "/get" calls. Returned as the maxObjectsInGet property value of the JMAP "urn:ietf:params:jmap:core" capabilities object.

jmap_max_objects_in_set

Default: 4096

The maximum number of objects a JMAP client may send to create, update or destroy in a single /set type method call. Returned as the maxObjectsInSet property value of the JMAP "urn:ietf:params:jmap:core" capabilities object.

jmap_max_size_blob_set

Default: 4M

The maximum size that the JMAP API accepts for Blob/upload. Returned as the maxSizeBlobSet property value of the JMAP "urn:ietf:params:jmap:blob" capabilities object.

For backward compatibility, if no unit is specified, kibibytes is assumed.

jmap_max_size_request

Default: 10M

The maximum size that the JMAP API accepts for requests at the API endpoint. Returned as the maxSizeRequest property value of the JMAP "urn:ietf:params:jmap:core" capabilities object.

For backward compatibility, if no unit is specified, kibibytes is assumed.

jmap_max_size_upload

Default: 1G

The maximum size that the JMAP API accepts for blob uploads. Returned as the maxSizeUpload property value of the JMAP "urn:ietf:params:jmap:core" capabilities object.

For backward compatibility, if no unit is specified, kibibytes is assumed.

jmap_nonstandard_extensions

Default: 0

If enabled, support non-standard JMAP extensions. If not enabled, only IETF standard JMAP functionality is supported.

jmap_preview_annot

Default: <none>

The name of the per-message annotation, if any, to store message previews.

jmap_preview_length

Default: 64B

The maximum length of dynamically generated message previews. Previews stored in jmap_preview_annot take precedence.

If no unit is specified, bytes is assumed.

jmap_pushpoll

Default: 60s

The interval for polling for changes on an EventSource connection or when push has been ennabled on a WebSocket channel. The minimum value is 1 second. A value of 0 will disable push.

If no unit is specified, seconds is assumed.

jmap_querycache_max_age

Specify how aliases dereferencing is handled during search.

Allowed values: search, find, always, never

ldap_domain_base_dn

Default: <empty string>

Base DN to search for domain name spaces.

ldap_domain_filter

Default: (&(objectclass=domainrelatedobject)(associateddomain=%s))

Filter to use searching for domains.

ldap_domain_name_attribute

Default: associateddomain

The attribute name for domains.

ldap_domain_result_attribute

Default: inetdomainbasedn

Result attribute

ldap_domain_scope

Default: sub

Search scope

Allowed values: sub, one, base

ldap_filter

Default: (uid=%u)

Specify a filter that searches user identifiers. The following tokens can be used in the filter string:

%%: %
%u: user
%U: user portion of %u (%U = test when %u = test@domain.tld)
%d: domain portion of %u if available (%d = domain.tld when %u = test@domain.tld), otherwise same as %R
%R: domain portion of %u starting with @ (%R = @domain.tld when %u = test@domain.tld)
%D: user dn (use when ldap_member_method is set to filter)
%1-9: domain tokens (%1 = tld, %2 = domain when %d = domain.tld)

ldap_filter is not used when ldap_sasl is enabled.

ldap_group_base

Default: <empty string>

LDAP base dn for ldap_group_filter.

ldap_group_filter

Default: (cn=%u)

Specify a filter that searches for group identifiers. See ldap_filter for more options.

ldap_group_scope

Default: sub

Default: sub

Specify search scope for ldap_member_filter.

Allowed values: sub, one, base

ldap_scope

Default: sub

Specify search scope.

Allowed values: sub, one, base

ldap_servers

Default: ldap://localhost/

Deprecated in favour of ldap_uri.

ldap_size_limit

Default: 1

Specify a number of entries for a search request to return.

ldap_start_tls

Default: 0

Use transport layer security for ldap:// using STARTTLS. Do not use ldaps:// in ldap_uri with this option enabled.

ldap_time_limit

Default: 5s

How long to wait for a search request to complete.

If no unit is specified, seconds is assumed.

ldap_timeout

Default: 5s

Default: \Snoozed

If enabled, failure to bind a port during startup is treated as a fatal error, causing master to shut down immediately. The default is to keep running, with the affected service disabled until the next SIGHUP causes it to retry.

Note that this only applies during startup. New services that fail to come up in response to a reconfig+SIGHUP will just be logged and disabled like the default behaviour, without causing master to exit.

master_pid_file

Default: {configdirectory}/master.pid

The path to a file that master(8) will write its PID to when running as a daemon.

master_ready_file

Default: {configdirectory}/master.ready

The path to a file that master(8) will update to indicate that it is ready to accept client connections. This file will be created if it does not already exist, or truncated if it does.

maxargssize

Default: 0

Maximum total size of arguments to an IMAP command that will be accepted by Cyrus. Commands with arguments that exceed this limit will be rejected.

If set to 0 (the default), a large internally-defined limit will be applied.

If no unit is specified, bytes is assumed.

maxheaderlines

Default: 1000

Maximum number of lines of header that will be processed into cache records. Default 1000. If set to zero, it is unlimited. If a message hits the limit, an error will be logged and the rest of the lines in the header will be skipped. This is to avoid malformed messages causing giant cache records.

maxliteral

Default: 128K

Maximum size of a single literal allowed by the IMAP parser.

If set to 0, a large internally-defined limit will be applied.

Literals used for message [part] data in APPEND are only limited by the maxmessagesize option.

If the literalminus option is enabled, non-synchonizing literals will be limited to the lesser of 4K and either maxliteral or maxmessagesize, depending on the use-case.

If no unit is specified, bytes is assumed.

maxlogins_per_host

Default: 0

Maximum number of logged in sessions allowed per service per host, zero means no limit.

maxlogins_per_user

Default: 0

Maximum number of logged in sessions allowed per service per user, zero means no limit.

maxmessagesize

Default: 0

Maximum size of messages that will be accepted by Cyrus. This affects LMTP deliveries, IMAP appends, DAV uploads, etc. Messages larger than this will be rejected.

If set to 0 (the default), a large internally-defined limit will be applied.

If no unit is specified, bytes is assumed.

maxquoted

Default: 128K

Maximum size of a single quoted string allowed by the IMAP parser.

If set to 0, a large internally-defined limit will be applied.

If no unit is specified, bytes is assumed.

maxword

Default: 128K

Maximum size of a single word allowed by the IMAP parser.

If set to 0, a large internally-defined limit will be applied.

If no unit is specified, bytes is assumed.

mboxkey_db

Default: twoskip

The cyrusdb backend to use for mailbox keys.

Allowed values: skiplist, twom, twoskip

mboxlist_db

Default: twoskip

munge8bit

Default: 1

If enabled, lmtpd munges messages with 8-bit characters in the headers. The 8-bit characters are changed to `X'. If reject8bit is enabled, setting munge8bit has no effect. (A proper solution to non-ASCII characters in headers is offered by RFC 2047 and its predecessors.)

mupdate_authname

Default: <none>

The SASL username (Authentication Name) to use when authenticating to the mupdate server (if needed).

mupdate_config

netscapeurl

Default: <none>

If enabled at compile time, this specifies a URL to reply when Netscape asks the server where the mail administration HTTP server is. Administrators should set this to a local resource.

newsaddheaders

Default: to

Space-separated list of headers to be added to incoming usenet articles. Added To: headers will contain email delivery addresses corresponding to each newsgroup in the Newsgroups: header. Added Reply-To: headers will contain email delivery addresses corresponding to each newsgroup in the Followup-To: or Newsgroups: header. If the specified header(s) already exist in an article, the email delivery addresses will be appended to the original header body(s).

This option applies if and only if the newspostuser option is set.

Allowed values: to, replyto

newsgroups

Default: *

A wildmat pattern specifying which mailbox hierarchies should be treated as newsgroups. Only mailboxes matching the wildmat will accept and/or serve articles via NNTP. If not set, a default wildmat of "*" (ALL shared mailboxes) will be used. If the newsprefix option is also set, the default wildmat will be translated to "<newsprefix>.*"

newsmaster

Default: news

Userid that is used for checking access controls when executing Usenet control messages. For instance, to allow articles to be automatically deleted by cancel messages, give the "news" user the 'd' right on the desired mailboxes. To allow newsgroups to be automatically created, deleted and renamed by the corresponding control messages, give the "news" user the 'c' right on the desired mailbox hierarchies.

newspeer

Default: <none>

A list of whitespace-separated news server specifications to which articles should be fed. Each server specification is a string of the form [user[:pass]@]host[:port][/wildmat] where 'host' is the fully qualified hostname of the server, 'port' is the port on which the server is listening, 'user' and 'pass' are the authentication credentials and 'wildmat' is a pattern that specifies which groups should be fed. If no 'port' is specified, port 119 is used. If no 'wildmat' is specified, all groups are fed. If 'user' is specified (even if empty), then the NNTP POST command will be used to feed the article to the server, otherwise the IHAVE command will be used.

A '@' may be used in place of '!' in the wildmat to prevent feeding articles cross-posted to the given group, otherwise cross-posted articles are fed if any part of the wildmat matches. For example, the string "peer.example.com:*,!control.*,@local.*" would feed all groups except control messages and local groups to peer.example.com. In the case of cross-posting to local groups, these articles would not be fed.

newspostuser

Default: <none>

Userid used to deliver usenet articles to newsgroup folders (usually via lmtp2nntp). For example, if set to "post", email sent to "post+comp.mail.imap" would be delivered to the "comp.mail.imap" folder.

When set, the Cyrus NNTP server will add the header(s) specified in the newsaddheaders option to each incoming usenet article. The added header(s) will contain email delivery addresses corresponding to each relevant newsgroup. If not set, no headers are added to usenet articles.

newsprefix

Default: <none>

Prefix to be prepended to newsgroup names to make the corresponding IMAP mailbox names.

newsrc_db_path

Default: <none>

The absolute path to the newsrc db file. If not specified, will be configdirectory/fetchnews.db

nntptimeout

Limit of partition usage (%): if a partition is over that limit, it is automatically excluded from selection mode.

If all partitions are over that limit, this feature is not used anymore.

partition_select_usage_reinit

Default: 0

For a given session, number of operations (e.g. partition selection) for which partitions usage data are cached.

plaintextloginalert

Default: <none>

Message to send to client after a successful plaintext login.

plaintextloginpause

Default: <none>

Time to pause after a successful plaintext login. For systems that support strong authentication, this permits users to perceive a cost of using plaintext passwords. (This does not affect the use of PLAIN in SASL authentications.)

If no unit is specified, seconds is assumed.

popexpiretime

Default: -1

The duration advertised as being the minimum a message may be left on the POP server before it is deleted (via the CAPA command, defined in the POP3 Extension Mechanism, which some clients may support). This duration has a granularity of whole days, with partial days truncated (so e.g. "45m" is effectively "0d"). "NEVER", the default, may be specified with a negative number.

The Cyrus POP3 server never deletes mail, no matter what the value of this parameter is. However, if a site implements a less liberal policy, it needs to change this parameter accordingly.

For backward compatibility, if no unit is specified, days is assumed.

popminpoll

Default: <none>

Set the minimum amount of time the server forces users to wait between successive POP logins.

For backward compatibility, if no unit is specified, minutes is assumed.

poppollpadding

Default: 1

Create a softer minimum poll restriction. Allows poppollpadding connections before the minpoll restriction is triggered. Additionally, one padding entry is recovered every popminpoll minutes. This allows for the occasional polling rate faster than popminpoll, (i.e., for clients that require a send/receive to send mail) but still enforces the rate long-term. Default is 1 (disabled).

The easiest way to think of it is a queue of past connections, with one slot being filled for every connection, and one slot being cleared every popminpoll minutes. When the queue is full, the user will not be able to check mail again until a slot is cleared. If the user waits a sufficient amount of time, they will get back many or all of the slots.

popsubfolders

Default: 0

Allow access to subfolders of INBOX via POP3 by using userid+subfolder syntax as the authentication/authorization id.

poptimeout

If no unit is specified, seconds is assumed.

proxy_authname

Default: proxy

The authentication name to use when authenticating to a backend server in the Cyrus Murder.

proxy_compress

Default: 0

Default: <none>

Unix domain socket that ptloader listens on.

(defaults to configdirectory/ptclient/ptsock).

pts_module

Default: afskrb

The PTS module to use.

Allowed values: afskrb, ldap, http

ptscache_db

Default: twoskip

The cyrusdb backend to use for the pts cache.

Allowed values: skiplist, twom, twoskip

ptscache_db_path

Default: <none>

The absolute path to the ptscache db file. If not specified, will be configdirectory/ptscache.db

ptscache_timeout

Default: 3h

The timeout for the PTS cache database when using the auth_krb_pts authorization method (default: 3 hours).

If no unit is specified, seconds is assumed.

ptskrb5_convert524

Default: 1

When using the AFSKRB ptloader module with Kerberos 5 canonicalization, do the final 524 conversion to get a n AFS style name (using '.' instead of '/', and using short names.

ptskrb5_strip_default_realm

Default: 1

When using the AFSKRB ptloader module with Kerberos 5 canonicalization, strip the default realm from the userid (this does not affect the stripping of realms specified by the afspts_localrealms option).

qosmarking

Default: cs0

This specifies the Class Selector or Differentiated Services Code Point designation on IP headers (in the ToS field).

Allowed values: cs0, cs1, cs2, cs3, cs4, cs5, cs6, cs7, af11, af12, af13, af21, af22, af23, af31, af32, af33, af41, af42, af43, ef

quota_db

Default: quotalegacy

The cyrusdb backend to use for quotas.

Allowed values: flat, skiplist, sql, quotalegacy, twom, twoskip

quota_db_path

Default: <none>

The absolute path for the quota database (if you choose a single-file quota DB type - or the base path if you choose quotalegacy). If not specified will be configdirectory/quotas.db or configdirectory/quota/

quota_use_conversations

Default: 0

If conversations it enabled and quotaroot is a user folder, use the conversations quota counts, which count multiple copies of exactly the same message (by GUID) as only one.

quotawarn

Default: 90

Deprecated in favour of quotawarnpercent.

quotawarnkb

Default: <none>

Deprecated in favour of quotawarnsize.

quotawarnmsg

Default: 0

The maximum amount of messages at which to give a quota warning (if this value is 0, or if the quota is smaller than this amount, then warnings are always given).

quotawarnpercent

Default: 90

The percent of quota utilization over which the server generates warnings.

quotawarnsize

search_attachment_extractor_request_timeout

Default: 5m

Defines the duration after which to cancel non-responding requests to the search attachment extractor service.

If no unit is specified, seconds is assumed.

search_attachment_extractor_url

Default: <none>

A HTTP or HTTPS URL to extract search text from rich text attachments and other media during search indexing. The server at this URL must implement the following protocol:

For each attachment of an email, Cyrus sends a GET request to the URL <extractor-url>/<cyrus-id>, where <extractor-url> is the configured URL and <cyrus-id> is a Cyrus-chosen path segment that uniquely identifies this attachment.
If the extractor already has a cached plain text extract of the attachment identified by <cyrus-id> then it may return HTTP status code 200 (OK) and the plain text extract with a Content-Type "text/plain" header. Otherwise it must return HTTP status 404 (Not Found).
If Cyrus receives the HTTP status code 404 (Not Found), then it sends a PUT request to the same URL as previously. The PUT request body contains the decoded, binary body of the attachment. The Content-Type request header has the same value as declared in the MIME part headers, including any type parameters.
The extractor must return the plain text extract with either HTTP status 200 (OK) or 201 (Created) and a Content-Type "text/plain" header. If no text can be extracted, then the extractor may return any return code in the range 4xx, or 200 and an empty response body.

Any other HTTP status code is treated as an error. For performance reasons, the Cyrus indexer attempts to keep-alive the TCP connection to the extractor. Xapian only.

search_batchsize

Default: 20

The number of messages to be indexed in one batch (default 20). Note that long batches may delay user commands or mail delivery.

search_engine

Default: none

The indexing engine used to speed up searching.

Allowed values: none, squat, xapian

search_fuzzy_always

Default: 0

Whether to enable RFC 6203 FUZZY search for all IMAP SEARCH. If turned on, search attributes will be searched using FUZZY search by default. If turned off, clients have to explicitly use the FUZZY search key to enable fuzzy search for regular SEARCH commands.

search_index_headers

Default: 1

Whether to index headers other than From, To, Cc, Bcc, and Subject. Experiment shows that some headers such as Received and DKIM-Signature can contribute up to 2/3rds of the index size but almost nothing to the utility of searching. Note that if header indexing is disabled, headers can still be searched, the searches will just be slower.

search_index_language

Default: 0

If enabled, then messages bodies are stemmed by detected language in addition to the default English stemmer. Xapian only.

search_index_parts

Default: 0

Deprecated. No longer used.

search_index_skip_domains

Default: <none>

A space separated list of domains - if set, any users in the listed domains will be skipped when indexing.

search_index_skip_users

Default: <none>

A space separated list of usernames - if set, any users in the list will be skipped when indexing.

search_indexed_db

Default: twoskip

The cyrusdb backend to use for the search latest indexed uid state. Xapian only.

Allowed values: flat, skiplist, twom, twoskip

search_maxsize

Default: 4M

The maximum size to index for each message part. Message contents that occur after this byte offset will not be indexed nor used to generate search snippets. Xapian-only.

For backward compatibility, if no unit is specified, kibibytes is assumed.

search_maxtime

Default: <none>

The maximum number of seconds to run a search for before aborting. Default of no value means search "forever" until other timeouts.

search_normalisation_max

Default: 1000

A resource bound for the combinatorial explosion of search expression tree complexity caused by normalising expressions with many OR nodes. These can use more CPU time to optimise than they save IO time in scanning folders.

search_query_language

Default: 0

Deprecated. No longer used.

search_queryscan

Default: 5000

The minimum number of records require to do a direct scan of all G keys rather than indexed lookups. A value of 0 means always do indexed lookups.

search_skipdiacrit

Default: 1

When searching, should diacriticals be stripped from the search terms. The default is "true", a search for "hav" will match "Håvard". This is not RFC 5051 compliant, but is backwards compatible, and may be preferred by some sites.

search_skiphtml

Default: 0

If enabled, HTML parts of messages are skipped, i.e. not indexed and not searchable. Otherwise, they're indexed.

search_snippet_length

Default: 255

The maximum byte length of a snippet generated by the XSNIPPETS command. Only supported by the Xapian search backend, which attempts to always fill search_snippet_length bytes in the generated snippet.

search_stopword_path

Default: <none>

The absolute base path to the search stopword lists. If not specified, no stopwords will be taken into account during search indexing. Currently, the only supported and default stop word file is english.txt.

search_whitespace

Default: merge

When searching, how whitespace should be handled. Options are: "skip" (default in 2.3 and earlier series) - where a search for "equi" would match "the quick brown fox". "merge" - the default, where "he qu" would match "the quick brownfox", and "keep", where whitespace must match exactly. The default of "merge" is recommended for most cases - it's a good compromise which keeps words separate.

Allowed values: skip, merge, keep

searchpartition-name

Default: <none>

The pathname where to store the xapian search indexes of searchtier for mailboxes of partition name. This must be configured for the defaultsearchtier and any additional search tier (see squatter(8) for details).

For example: if defaultpartition is defined as part1 and defaultsearchtier as tier1 then the configuration must contain an entry tier1searchpartition-part1 that defines the path where to store this tier1's search index for the part1 partition.

This option MUST be specified for xapian search.

seenstate_db

Default: twoskip

The cyrusdb backend to use for the seen state.

Allowed values: flat, skiplist, twom, twoskip

sendmail

Default: /usr/lib/sendmail

The pathname of the sendmail executable. Sieve invokes sendmail for sending rejections, redirects and vacation responses.

sendmail_auth_id

Default: CYRUS_SENDMAIL_AUTH_ID

The name of an environment variable to set when invoking sendmail. The value of this environment variable will contain the user id of the currently authenticated user. If no user is authenticated the environment variable is not set.

serverinfo

Default: on

The server information to display in the greeting and capability responses. Information is displayed as follows:

off: no server information in the greeting or capabilities
min: servername in the greeting; no server information in the capabilities
on: servername and product version in the greeting; product version in the capabilities

Allowed values: off, min, on

serverlist

Default: <none>

Whitespace separated list of backend server names. Used for finding server with the most available free space for proxying CREATE.

serverlist_select_mode

Default: freespace-most

Server selection mode.

random: (pseudo-)random selection
freespace-most: backend with the most (total) free space (KiB)
freespace-percent-most: backend whose partition has the most free space (%)
freespace-percent-weighted: same as for partition selection, comparing the free space (%) of the least used partition of each backend
freespace-percent-weighted-delta: same as for partition selection, comparing the free space (%) of the least used partition of each backend.

Allowed values: random, freespace-most, freespace-percent-most, freespace-percent-weighted, freespace-percent-weighted-delta

serverlist_select_soft_usage_limit

Default: 0

Limit of backend usage (%): if a backend is over that limit, it is automatically excluded from selection mode.

If all backends are over that limit, this feature is not used anymore.

serverlist_select_usage_reinit

Default: 0

For a given session, number of operations (e.g. backend selection) for which backend usage data are cached.

servername

Default: <none>

This is the hostname visible in the greeting messages of the POP, IMAP and LMTP daemons. If it is unset, then the result returned from gethostname(2) is used. This is also the value used by murder clusters to identify the host name. It should be resolvable by DNS to the correct host, and unique within an active cluster. If you are using low level replication (e.g. drbd) then it should be the same on each copy and the DNS name should also be moved to the new master on failover.

sharedprefix

Default: Shared Folders

If using the alternate IMAP namespace, the prefix for the shared namespace. The hierarchy delimiter will be automatically appended.

sieve_allowreferrals

Default: 1

If enabled, timsieved will issue referrals to clients when the user's scripts reside on a remote server (in a Murder). Otherwise, timsieved will proxy traffic to the remote server.

sieve_duplicate_max_expiration

Default: 90d

Maximum expiration time for duplicate message tracking records.

If no unit is specified, seconds is assumed.

sieve_extensions

Default: fileinto reject vacation vacation-seconds notify include envelope environment body relational regex subaddress copy date index imap4flags mailbox mboxmetadata servermetadata variables editheader extlists duplicate ihave fcc special-use redirect-dsn redirect-deliverby mailboxid vnd.cyrus.log vnd.cyrus.jmapquery processcalendar snooze vnd.cyrus.implicit_keep_target vnd.cyrus.redirect-multiple

Space-separated list of Sieve extensions allowed to be used in sieve scripts. This option has no effect on options that are disabled at compile time (e.g., "regex").

Allowed values: fileinto, reject, vacation, vacation-seconds, notify, include, envelope, environment, body, relational, regex, subaddress, copy, date, index, imap4flags=imapflags, mailbox, mboxmetadata, servermetadata, variables, editheader, extlists, duplicate, ihave, fcc, special-use, redirect-dsn, redirect-deliverby, mailboxid, vnd.cyrus.log=x-cyrus-log, vnd.cyrus.jmapquery=x-cyrus-jmapquery, processcalendar=vnd.cyrus.imip, snooze=vnd.cyrus.snooze=x-cyrus-snooze, vnd.cyrus.implicit_keep_target, vnd.cyrus.redirect-multiple

sieve_folder

Default: #sieve

The name of the folder for storing Sieve scripts.

sieve_maxscripts

Default: 5

Maximum number of sieve scripts any user may have, enforced at submission by timsieved(8).

sieve_maxscriptsize

Default: 32K

Maximum size any sieve script can be, enforced at submission by timsieved(8) and JMAP.

For backward compatibility, if no unit is specified, kibibytes is assumed.

sieve_mdn_original_recipient_header

Default: original-recipient

The name of the header field in which the Sieve "reject" action can find the original recipient of the message.

sieve_mdn_private

Default: 0

If true, the Final-Recipient header in the MDN generated by Sieve's "reject" action will be replaced with something that does not publicly identify the user.

sieve_sasl_send_unsolicited_capability

Default: 1

Deprecated. No longer used.

sieve_use_lmtp_reject

Default: 1

Enabled by default. If reject can be done via LMTP, then return a 550 rather than generating the bounce message in Cyrus.

sieve_utf8fileinto

Default: 0

If enabled, the sieve engine expects folder names for the fileinto action in scripts to use UTF8 encoding. Otherwise, modified UTF7 encoding should be used.

sieve_vacation_max_response

Default: 90d

Maximum time interval between consecutive vacation responses, per RFC 6131. The default is 90 days. The minimum is 7 days.

If no unit is specified, seconds is assumed.

sieve_vacation_min_response

Default: 3d

Minimum time interval between consecutive vacation responses, per RFC 6131. The default is 3 days.

If no unit is specified, seconds is assumed.

sievedir

Default: /usr/sieve

If sieveusehomedir is false, this directory is searched for Sieve scripts.

sievenotifier

The host backend sends message submissions via a TCP socket to the SMTP host defined in the config option smtp_host.

The sendmail backend forks the Cyrus process into the executable defined in the config option sendmail. The executable must accept "-bs" as command line argument, read from stdin and must implement the minimum SMTP protocol as defined in section 4.5.1 of RFC 5321.

If the SMTP EHLO command reports AUTH (RFC 4954) as a supported extension, then the MAIL FROM command includes the AUTH parameter, with its value set to the name of any authenticated user which triggered the email. The AUTH parameter is omitted if the user is unknown to the calling process.

If the directory configdirectory/log/smtpclient.smtp_backend exists, then telemetry logs for outgoing SMTP sessions will be created in this directory.

Allowed values: host, sendmail

smtp_host

Default: twoskip

The cyrusdb backend to use for the imap status cache.

Allowed values: skiplist, sql, twom, twoskip

statuscache_db_path

Default: <none>

The absolute path to the statuscache db file. If not specified, will be configdirectory/statuscache.db

submitservers

Default: <none>

A list of users and groups that are allowed to resolve "urlauth=submit+" IMAP URLs, separated by spaces. Any user listed in this will be allowed to fetch the contents of any valid "urlauth=submit+" IMAP URL: use with caution.

subscription_db

Default: flat

The cyrusdb backend to use for the subscriptions list.

Allowed values: flat, skiplist, twom, twoskip

suppress_capabilities

Default: <none>

Suppress the named capabilities from any capability response. Use the exact case as it appears in the response, e.g. "suppress_capabilities: ESEARCH QRESYNC WITHIN XLIST LIST-EXTENDED" if you have a murder with 2.3.x backends and don't want clients being confused by new capabilities that some backends don't support.

sync_authname

Default: <none>

The authentication name to use when authenticating to a sync server. Prefix with a channel name to only apply for that channel.

sync_batchsize

Default: 8192

the number of messages to upload in a single mailbox replication. Default is 8192. If there are more than this many messages appended to the mailbox, generate a synthetic partial state and send that.

sync_cache_db

Default: twoskip

sync_log_unsuppressable_channels

Default: squatter

If specified, the named channels are exempt from the effect of setting sync_log_chain: off, i.e. they are always logged to by the sync_server process. This is only really useful to allow rolling search indexing on a replica.

sync_password

Default: <none>

The default password to use when authenticating to a sync server. Prefix with a channel name to only apply for that channel.

sync_port

Default: <none>

Name of the service (or port number) of the replication service on replica host. Prefix with a channel name to only apply for that channel. If not specified, and if sync_try_imap is set to "yes" (the default), then the replication client will first try "imap" (port 143) to check if imapd supports replication. Otherwise it will default to "csync" (usually port 2005).

sync_realm

Default: <none>

The authentication realm to use when authenticating to a sync server. Prefix with a channel name to only apply for that channel.

sync_reconnect_maxwait

Default: 0

If true, log by sessionid instead of PID for telemetry.

temp_path

Default: /tmp

The pathname to store temporary files in. It is recommended to use an in-memory filesystem such as tmpfs for this path.

timeout

Default: 32m

https://wiki.mozilla.org/Security/Server_Side_TLS .

tls_client_ca_dir

Default: <none>

Path to a directory containing the CA certificates used to verify client SSL certificates used for authentication.

tls_client_ca_file

Default: <none>

Path to a file containing the CA certificate(s) used to verify client SSL certificates used for authentication.

tls_client_cert

Default: <none>

File containing the certificate presented to a server for authentication during STARTTLS. A value of "disabled" will disable this server's use of certificate-based authentication.

tls_client_certs

Default: optional

Default: 24h

The length of time that a TLS session will be cached for later reuse. The maximum value is 24 hours, also the default. A value of 0 will disable session caching.

For backward compatibility, if no unit is specified, minutes is assumed.

tls_sessions_db

Default: twoskip

The cyrusdb backend to use for the TLS cache.

Allowed values: skiplist, sql, twom, twoskip

tls_sessions_db_path

Default: <none>

The absolute path to the TLS sessions db file. If not specified, will be configdirectory/tls_sessions.db

tls_versions

Default: tls1_0 tls1_1 tls1_2 tls1_3

A list of SSL/TLS versions to not disable. Cyrus IMAP SSL/TLS starts with all protocols, and subtracts protocols not in this list. Newer versions of SSL/TLS will need to be added here to allow them to get disabled.

Default: 0

Maximum allowed vCard size.

If non-zero, CardDAV and JMAP will reject storage of contacts whose vCard representation is larger than vcard_max_size.

If set to 0 (the default), a large internally-defined limit will be applied.

If no unit is specified, bytes is assumed.

virtdomains

Default: off

Configure virtual domain support.

off: Cyrus does not know or care about domains. Only the local part of email addresses is ever considered. This is not recommended for any deployment, but is currently the default.
userid: The user's domain is determined by splitting a fully qualified userid at the last '@' or '%' symbol. If the userid is unqualified, the defaultdomain will be used. This is the recommended configuration for all deployments. If you wish to provide calendaring services you must use this configuration.
on: Fully qualified userids are respected, as per userid. Unqualified userids will have their domain determined by doing a reverse lookup on the IP address of the incoming network interface, or if no record is found, the defaultdomain will be used.

Allowed values: off, userid, on

virusscan_notification_subject

Default: Automatically deleted mail

The text used in the subject of email notifications created by cyr_virusscan(8) when deleting infected mail.

virusscan_notification_template

Default: <none>

The absolute path to a file containing a template to use to describe infected messages that have been deleted by cyr_virusscan(8). See cyr_virusscan(8) for specification of the format of this file. If not specified, the builtin default template will be used.

webdav_attachments_baseurl

Default: <none>

The base URL for WebDAV managed attachments, excluding the Cyrus-specific URL paths. Typically, this only includes the HTTP scheme and host name at which DAV clients may fetch managed attachments from, e.g. "https://dav.example.com". If not specified, the target host of the DAV HTTP request that uploaded the attachment will be used. For JMAP, the Link.blobId property of JSCalendar objects will be disabled.

webdav_attachments_max_binary_attach_size

Default: 1024K

The maximum byte length of an ATTACH property value when managed attachment URIs get rewritten to BINARY during iTIP processing. Any attachment that exceeds this byte size keeps its managed attachment URI as ATTACH value. A zero size limit causes attachments of any size be rewritten as BINARY.

For backward compatibility, if no unit is specified, kibibytes is assumed.

websocket_timeout

Default: 30m

Set the length of the HTTP server's inactivity autologout timer when a WebSocket channel has been established. The default is 30 minutes. The minimum value is 0, which will disable WebSockets.

For backward compatibility, if no unit is specified, minutes is assumed.

xbackup_enabled

Default: 0

Deprecated. No longer used.

xlist-flag

Default: <none>

Set the special-use flag flag on the specified folder when it is autocreated (see the autocreate_inbox_folders option). For example, if xlist-junk: Spam is set, and the folder Spam is autocreated, the special-use flag \Junk will be set on it.

(This option is so named for backward compatibility with old config files.)

zoneinfo_db

Default: twoskip

The cyrusdb backend to use for zoneinfo. This database is used by the "tzdist" httpmodule, and is managed by ctl_zoneinfo(8).

Allowed values: flat, skiplist, twom, twoskip

zoneinfo_db_path

Default: <none>

The absolute path to the zoneinfo db file. If not specified, will be configdirectory/zoneinfo.db

zoneinfo_dir

Default: <none>

The absolute path to the zoneinfo directory, containing timezone definitions as generated by the vzic tool. This overrides any compile-time value that was set with the --with-zoneinfo-dir configure option.

If not specified, and no compile-time value was set, then whatever definitions libical finds will be used.

If you are providing a Time Zone Data Distribution Service (i.e. you have "tzdist" listed in httpmodules), then this configuration option or a compile time value MUST be specified.

imapd.conf

DESCRIPTION

OPTION DESCRIPTIONS

@include

acl_admin_implies_write

addressbookprefix

admins

admins_get_internal_seen

afspts_localrealms

afspts_mycell

allowallsubscribe

allowanonymouslogin

allowapop

allowdeleted

allownewnews

allowplaintext

allowsetacl

allowspecialusesubfolder

allowstarttls

allowusermoves

altnamespace

altprefix

annotation_allow_undefined

annotation_callout

annotation_callout_disable_append

annotation_db

annotation_db_path

annotation_definitions

annotation_enable_legacy_commands

anyoneuseracl

anysievefolder

aps_expiry

aps_topic

aps_topic_caldav

aps_topic_carddav

archive_after

archive_days

archive_enabled

archive_keepflagged

archive_maxsize

archivepartition-name

auditlog

auth_mech

autocreate_acl

autocreate_inbox_folders

autocreate_post

autocreate_quota

autocreate_quota_messages

autocreate_sieve_compiled_script

autocreate_sieve_folders

autocreate_sieve_script

autocreate_sieve_script_compile

autocreate_sieve_script_compiled

autocreate_subscribe_folders

autocreate_subscribe_sharedfolders

autocreate_subscribe_sharedfolders_all

autocreate_users

autocreateinboxfolders

autocreatequota

autocreatequotamsg

autoexpunge

autosievefolders

autosubscribe_all_sharedfolders

autosubscribeinboxfolders

autosubscribesharedfolders

backup_compact_maxsize

backup_compact_minsize

backup_compact_work_threshold

backup_db

backup_db_path

backup_keep_previous

backup_retention

backup_retention_days

backup_staging_path

backuppartition-name

boundary_limit

caldav_accept_invalid_rrules

caldav_alarm_db_path

caldav_alarm_support_components

caldav_alarm_suppress_file