Provided by: cyrus-common_3.0.11-1_amd64 bug

NAME

       imapd.conf - Cyrus IMAP documentation

       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.

FIELD 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>''.

          addressbookprefix: #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: <empty string>
              The list of userids with administrative rights.  Separate each userid with a space.
              Sites using Kerberos authentication may use separate "admin" instances.

              Note  that  accounts  used  by  users should not be administrators.  Administrative
              accounts should not receive mail.  That is, if user "jbRo" is a user reading  mail,
              he  should not also be in the admins line.  Some problems may occur otherwise, most
              notably the ability of administrators to  create  top-level  mailboxes  visible  to
              users, but not writable by users.

          afspts_localrealms: <none>
              The  list  of  realms  which  are  to be treated as local, and thus stripped during
              identifier canonicalization (for the AFSPTS ptloader module).   This  is  different
              from  loginrealms in that it occurs later in the authorization process (as the user
              id is canonified for PTS lookup)

          afspts_mycell: <none>
              Cell to use for AFS PTS lookups.  Defaults to the local cell.

          allowallsubscribe: 0
              Allow subscription to nonexistent mailboxes.  This  option  is  typically  used  on
              backend  servers  in  a  Murder so that users can subscribe to mailboxes that don't
              reside on their "home" server.  This option can also be used as  a  workaround  for
              IMAP  clients  which  don't  play  well  with nonexistent or unselectable mailboxes
              (e.g., Microsoft Outlook).

          allowanonymouslogin: 0
              Permit logins by the user "anonymous" using any password.  Also allows use  of  the
              SASL ANONYMOUS mechanism.

          allowapop: 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.

          allownewnews: 0
              Allow use of the NNTP NEWNEWS command.

              Note that this is a  very  expensive  command  and  should  only  be  enabled  when
              absolutely necessary.

          allowplaintext: 0
              If enabled, allows the use of cleartext passwords on the wire.

              By  default,  the use of cleartext passwords requires a TLS/SSL encryption layer to
              be negotiated prior to any cleartext authentication mechanisms being advertised  or
              allowed.   To  require  a  TLS/SSL  encryption  layer to be negotiated prior to ANY
              authentication, see the tls_required option.

          allowusermoves: 0
              Allow moving user accounts (with associated meta-data) via RENAME or XFER.

              Note that measures should be taken to make sure that the user being  moved  is  not
              logged  in,  and  cannot login during the move.  Failure to do so may result in the
              user's meta-data (seen state, subscriptions, etc) being corrupted or out of date.

          altnamespace: 1
              Use the alternate IMAP namespace, where personal folders reside at the  same  level
              in the hierarchy as INBOX.

              This  option  ONLY  applies  where  interaction  takes  place with the client/user.
              Currently this is limited to the IMAP protocol (imapd) and Sieve  scripts  (lmtpd).
              This  option  does  NOT  apply  to  admin  tools  such  as  cyradm  (admins  ONLY),
              reconstruct, quota, etc., NOR does it affect LMTP delivery of messages directly  to
              mailboxes via plus-addressing.  The default changed in 3.0 from off to on.

          altprefix: Alt Folders
              Alternative  INBOX  spellings  that  can't be accessed in altnamespace otherwise go
              under here

          annotation_db: twoskip
              The cyrusdb backend to use for mailbox annotations.

              Allowed values: skiplist, twoskip, lmdb

          annotation_db_path: <none>
              The absolute  path  to  the  annotations  db  file.   If  not  specified,  will  be
              configdirectory/annotations.db

          anyoneuseracl: 1
              Should  non-admin  users  be  allowed  to  set  ACLs for the 'anyone' user on their
              mailboxes?  In a large organization this  can  cause  support  problems,  but  it's
              enabled by default.

          annotation_allow_undefined: 0
              Allow  clients to store values for entries which are not defined either by Cyrus or
              in the annotations_definitions file.

          annotation_definitions: <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
                     specifies whether this attribute is for the backend or proxy servers or both
                     (proxy_and_backend)

              attrib-names
                     is the space-separated list of  available  attributes  for  the  annotation.
                     Possible  attribute  names  are  value.shared,  value.priv, and value (which
                     permits both  value.priv  and  value.shared).   The  attribute  names  size,
                     size.shared,  and  size.priv  are accepted but ignored; these attributes are
                     automatically provided by the server if the corresponding value attribute is
                     specified.  Some obsolete attributes, which were defined early drafts of the
                     standard, are accepted and ignored with a warning.

              extra-permissions
                     is the extra ACL permission bits required for setting  this  annotation,  in
                     standard  IMAP  ACL  permission  bit  string  format.   Note that this is in
                     addition to the permission bits specified in  RFC  5257  and  RFC  5464,  so
                     leaving  this  field  empty  is harmless.  Note also that there is no way to
                     specify that an annotation can only be set by an admin user;  in  particular
                     the a permission bit does not achieve this.

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

          annotation_callout: <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.

          aps_topic: <none>
              Topic for Apple Push Service registration.

          aps_topic_caldav: <none>
              Topic for Apple Push Service registration for CalDAV.

          aps_topic_carddav: <none>
              Topic for Apple Push Service registration for CardDAV.

          archive_enabled: 0
              Is  archiving  enabled  for this server.  You also need to have an archivepartition
              for the mailbox.  Archiving allows older email to  be  stored  on  slower,  cheaper
              disks - even within the same mailbox, as distinct from partitions.

          archive_days: 7
              The  number  of  days  after  which  to  move  messages to the archive partition if
              archiving is enabled

          archive_maxsize: 1024
              The size in kilobytes of the largest message that won't  be  archived  immediately.
              Default is 1Mb

          archive_keepflagged: 0
              If set, messages with the \Flagged system flag won't be archived, provided they are
              smaller than archive_maxsize.

          archivepartition-name: <none>
              The pathname of the  archive  partition  name,  corresponding  to  spool  partition
              partition-name.   For  any  mailbox  residing in a directory on partition-name, the
              archived   messages   will   be   stored   in   a   corresponding   directory    on
              archivepartition-name.   Note  that  not  every  partition-name  option is strictly
              required to have a corresponding archivepartition-name option, but that without one
              there's no benefit to enabling archiving.

          auditlog: 0
              Should  cyrus  output  log  entries  for  every  action  taken on a message file or
              mailboxes list entry?  It's noisy so disabled by default, but can  be  very  useful
              for tracking down what happened if things look strange

          auth_mech: unix
              The authorization mechanism to use.

              Allowed values: unix, pts, krb, krb5

          autocreateinboxfolders: <none>
              Deprecated in favor of autocreate_inbox_folders.

          autocreatequota: 0
              Deprecated in favor of autocreate_quota.

          autocreatequotamsg: -1
              Deprecated in favor of autocreate_quota_messages.

          autosievefolders: <none>
              Deprecated in favor of autocreate_sieve_folders.

          generate_compiled_sieve_script: 0
              Deprecated in favor of autocreate_sieve_script_compile.

          autocreate_sieve_compiled_script: <none>
              Deprecated in favor of autocreate_sieve_script_compiled.

          autosubscribeinboxfolders: <none>
              Deprecated in favor of autocreate_subscribe_folders.

          autosubscribesharedfolders: <none>
              Deprecated in favor of autocreate_subscribe_sharedfolders.

          autosubscribe_all_sharedfolders: 0
              Deprecated in favor of autocreate_subscribe_sharedfolders_all.

          autocreate_inbox_folders: <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:

              1. The user logins via the IMAP or the POP3 protocol.  autocreate_quota option must
                 have a value of zero or greater.

              2. A  message  arrives  for  the user through the lmtpd(8).  autocreate_post option
                 must be enabled.

          autocreate_post: 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(8) and delivery of the
              message continues.

          autocreate_quota: -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 is specified in kilobytes.

          autocreate_quota_messages: -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_folders: <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: <none>
              The full path of a file that contains a sieve  script.  This  script  automatically
              becomes a user's initial default sieve filter script.

              When this option is not defined, no default sieve filter is created.  The file must
              be readable by the Cyrus daemon.

          autocreate_sieve_script_compile: 0
              If set to yes and no compiled sieve script file exists, the sieve script  which  is
              compiled    on    the    fly    will    be    saved   in   the   file   name   that
              autocreate_sieve_compiledscript option points to. In order a compiled script to  be
              generated,  autocreate_sieve_script  and  autocreate_sieve_compiledscript must have
              valid values

          autocreate_sieve_script_compiled: <none>
              The full path of a file that contains a compiled in  bytecode  sieve  script.  This
              script automatically becomes a user's initial default sieve filter script.  If this
              option is not specified, or the filename doesn't exist then the script  defined  by
              autocreate_sieve_script  is compiled on the fly and installed as the user's default
              sieve script

          autocreate_subscribe_folders: <none>
              A list of folder  names,  separated  by  "|",  that  the  users  get  automatically
              subscribed  to,  when  their  INBOX  is  created. These folder names must have been
              included in the autocreateinboxfolders option of the imapd.conf.

          autocreate_subscribe_sharedfolders: <none>
              A list of shared folders (bulletin boards), separated by "|", that  the  users  get
              automatically  subscribed  to, after their INBOX is created. The shared folder must
              have been created and the user must have the required permissions to get subscribed
              to it. Otherwise, subscribing to the shared folder fails.

          autocreate_subscribe_sharedfolders_all: 0
              If  set to yes, the user is automatically subscribed to all shared folders, one has
              permission to subscribe to.

          autocreate_users: anyone
              A space separated list of users and/or groups that are allowed their  INBOX  to  be
              automatically created.

          backuppartition-name: <none>
              The  pathname of the backup partition name.  At least one backup partition pathname
              MUST be specified if backups are in  use.   Note  that  there  is  no  relationship
              between spool partitions and backup partitions.

          backup_compact_minsize: 0
              The  minimum size in kilobytes of chunks in each backup.  The compact tool will try
              to combine adjacent chunks that are smaller than this.

              Setting this value to zero or negative disables combining of chunks.

          backup_compact_maxsize: 0
              The maximum size in kilobytes of chunks in each backup.  The compact tool will  try
              to split chunks larger than this into smaller chunks.

              Setting this value to zero or negative disables splitting of chunks.

          backup_compact_work_threshold: 1
              The  number  of  chunks that must obviously need compaction before the compact tool
              will go ahead with the compaction.  If set to less than one, the value  is  treated
              as being one.

          backup_staging_path: <none>
              The  absolute  path  of  the  backup  staging  area.   If  not  specified,  will be
              temp_path/backup

          backup_retention_days: 7
              The number of days to keep content in backup after it has  been  deleted  from  the
              source.   If  set  to  a  negative  value  or  zero,  deleted  content will be kept
              indefinitely.

          backup_db: twoskip
              The cyrusdb backend to use for the backup locations database.

              Allowed values: skiplist, sql, twoskip, lmdb

          backup_db_path: <none>
              The  absolute  path  to  the  backup  db  file.   If   not   specified,   will   be
              configdirectory/backups.db

          backup_keep_previous: 0
              Whether  the  ctl_backups  compact and ctl_backups reindex commands should preserve
              the original file.  The original file will be  named  with  a  timestamped  suffix.
              This is mostly useful for debugging.

              Note  that  with  this enabled, compacting a backup will actually increase the disk
              used by it (because there will now be an extra copy: the original version, and  the
              compacted version).

          boundary_limit: 1000
              messages  are parsed recursively and a deep enough MIME structure can cause a stack
              overflow.  Do not parse deeper than  this  many  layers  of  MIME  structure.   The
              default of 1000 is much higher than any sane message should have.

          caldav_allowattach: 1
              Enable managed attachments support on the caldav server.

          caldav_allowscheduling: 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: 1
              Create the 'Attachments' calendar if it doesn't already exist

          caldav_create_default: 1
              Create the 'Default' calendar if it doesn't already exist

          caldav_create_sched: 1
              Create the 'Inbox' and 'Outbox' calendars if they don't already exist

          caldav_maxdatetime: 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  utility  in  order  to see its effect on
              serer-side time-based queries.

          caldav_mindatetime: 19011213T204552Z
              The earliest date and time accepted by the server (ISO format).

          caldav_realm: <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.

          calendarprefix: #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.

          calendar_user_address_set: <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 "servername"
              option will be used.

          carddav_realm: <none>
              The realm to present for HTTP authentication of CardDAV resources.  If not set (the
              default), the value of the "servername" option will be used.

          carddav_repair_vcard: 0
              If  enabled,  VCARDs  with  invalid  content  are  attempted  to be repaired during
              creation.

          chatty: 0
              If yes, syslog tags and commands for every IMAP command, mailboxes for  every  lmtp
              connection, every POP3 command, etc

          client_bind: 0
              If  enabled,  a  specific  IP  will  be  bound when performing a client connection.
              client_bind_name is used if it is set,  otherwise  servername  is  used.   This  is
              useful   on  multi-homed  servers  where  Cyrus  should  not  use  other  services'
              interfaces.

              If not enabled (the default), no bind will be performed.  Client  connections  will
              use an IP chosen by the operating system.

          client_bind_name: <none>
              IPv4,  IPv6  address or hostname to bind for client connections when client_bind is
              enabled.  If not set (the default), servername will be used.

          client_timeout: 10
              Number of seconds to wait before returning a  timeout  failure  when  performing  a
              client connection (e.g., in a murder environment)

          commandmintimer: <none>
              Time in seconds. Any imap command that takes longer than this time is logged.

          configdirectory: <none>
              The pathname of the IMAP configuration directory.  This field is required.

          createonpost: 0
              Deprecated in favor of autocreate_post.

          conversations: 0
              Enable  the  XCONVERSATIONS  extensions.  Extract conversation tracking information
              from incoming messages and track them in per-user databases.

          conversations_counted_flags: <none>
              space-separated list of flags for which per-conversation counts will be kept.  Note
              that you need to reconstruct the conversations database with ctl_conversationsdb if
              you change this option on a running server, or the counts will be wrong.

          conversations_db: skiplist
              The cyrusdb backend to use for the per-user conversations database.

              Allowed values: skiplist, sql, twoskip, lmdb

          conversations_expire_days: 90
              How long the conversations database keeps the message tracking  information  needed
              for receiving new messages in existing conversations, in days.

          crossdomains: 0
              Enable cross domain sharing.  This works best with alt namespace and unix hierarchy
              separators on, so you get Other Users/foo@example.com/...

          crossdomains_onlyother: 0
              only show the domain for users in  other  domains  than  your  own  (for  backwards
              compatibility if you're already sharing

          cyrus_group: <none>
              The  name  of the group Cyrus services will run as.  If not configured, the primary
              group of cyrus_user will  be  used.  Can  be  further  overridden  by  setting  the
              $CYRUS_GROUP environment variable.

          cyrus_user: <none>
              The  username  to  use  as  the  'cyrus' user.  If not configured, the compile time
              default will be  used.  Can  be  further  overridden  by  setting  the  $CYRUS_USER
              environment variable.

          davdriveprefix: #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: #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.

          dav_realm: <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.

          debug_command: <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 (without
              path).  The second is the pid (integer) and the third is the service ID.   Example:
              /usr/local/bin/gdb /usr/cyrus/bin/%s %d

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

          defaultdomain: internal
              The default domain for virtual domain support

          defaultpartition: <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: <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  the  man  page  of  squatter for details. The default search tier also
              requires the definition of an according searchtierpartition-name entry.

              This option MUST be specified for xapian search.

          defaultserver: <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.

          deletedprefix: DELETED
              With  delete_mode  set to delayed, the deletedprefix setting defines the prefix for
              the hierarchy of deleted mailboxes.

              The hierarchy delimiter will be automatically appended.

          delete_mode: 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: 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.  The default is 'no'.

          deleteright: c
              Deprecated - only used for backwards  compatibility  with  existing  installations.
              Lists the old RFC 2086 right which was used to grant the user the ability to delete
              a mailbox.  If a user has this right, they will automatically be given the new  'x'
              right.

          disable_user_namespace: 0
              Preclude  list  command on user namespace.  If set to 'yes', the LIST response will
              never include any other user's mailbox.  Admin users will always see all mailboxes.
              The default is 'no'

          disable_shared_namespace: 0
              Preclude list command on shared namespace.  If set to 'yes', the LIST response will
              never include any non-user mailboxes.  Admin users will always see  all  mailboxes.
              The default is 'no'

          disconnect_on_vanished_mailbox: 0
              If  enabled,  IMAP/POP3/NNTP  clients  will  be  disconnected  by the server if the
              currently selected mailbox is (re)moved by another session.  Otherwise, the missing
              mailbox is treated as empty while in use by the client.

          ischedule_dkim_domain: <none>
              The domain to be reported as doing iSchedule DKIM signing.

          ischedule_dkim_key_file: <none>
              File containing the private key for iSchedule DKIM signing.

          ischedule_dkim_selector: <none>
              Name  of  the selector subdividing the domain namespace.  This specifies the actual
              key used for iSchedule DKIM signing within the domain.

          duplicate_db: twoskip
              The cyrusdb backend to use  for  the  duplicate  delivery  suppression  and  sieve.
              Allowed values: skiplist, sql, twoskip, lmdb

          duplicate_db_path: <none>
              The   absolute  path  to  the  duplicate  db  file.   If  not  specified,  will  be
              configdirectory/deliver.db

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

          event_exclude_flags: <none>
              Don't send event notification for given IMAP flag(s)

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

          event_extra_params: 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

          event_groups: message mailbox
              Space-separated list of groups of related events to turn on notification

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

          event_notifier: <none>
              Notifyd(8) method to use for "EVENT" notifications which are based on the RFC 5423.
              If not set, "EVENT" notifications are disabled.

          expunge_mode: delayed
              The mode in which messages (and their corresponding cache  entries)  are  expunged.
              "default"  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.   (Note  that this behaviour is no longer the default, but is so named for
              historical reasons.)  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  "default" 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: default, immediate, delayed

          failedloginpause: 3
              Number of seconds to pause after a failed login.

          flushseenstate: 1
              Deprecated. No longer used

          foolstupidclients: 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: <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: 0
              If enabled, uses an improved directory hashing scheme which hashes  on  the  entire
              username  instead  of  using  just the first letter as the hash.  This changes hash
              algorithm used for quota and user directories and if hashimapspool is enabled,  the
              entire mail spool.

              Note  that  this  option  CANNOT  be  changed on a live system.  The server must be
              quiesced and then the directories moved with the rehash utility.

          hashimapspool: 0
              If enabled, the partitions will also be hashed, in addition to the hashing done  on
              configuration  directories.   This is recommended if one partition has a very bushy
              mailbox tree.

          debug: 0
              If enabled, allow syslog() to pass LOG_DEBUG messages.

          hostname_mechs: <none>
              Force a particular list of SASL mechanisms to be used when  authenticating  to  the
              backend  server  hostname  (where  hostname  is the short hostname of the server in
              question). If it is not specified it will query the server for available mechanisms
              and pick one to use. - Cyrus Murder

          hostname_password: <none>
              The  password  to  use  for  authentication  to  the backend server hostname (where
              hostname is the short hostname of the server) - Cyrus Murder

          httpallowcompress: 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: <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").

          httpallowtrace: 0
              Allow use of the TRACE method.

              Note that sensitive data might be disclosed by the response.

          httpallowedurls: <none>
              Space-separated list of relative URLs (paths) rooted at "httpdocroot"  (see  below)
              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.

          httpcontentmd5: 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: <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: 20
              Set the length of the HTTP server's keepalive heartbeat in seconds.  The default is
              20.   The  minimum  value  is  0, which will disable the keepalive heartbeat.  When
              enabled, if a request takes longer  than  httpkeepalive  seconds  to  process,  the
              server will send the client provisional responses every httpkeepalive seconds until
              the final response can be sent

          httpmodules: <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, domainkey, freebusy, ischedule, rss, tzdist, webdav

          httpprettytelemetry: 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.

          httptimeout: 5
              Set  the  length of the HTTP server's inactivity autologout timer, in minutes.  The
              default is 5.  The minimum value is 0, which will disable persistent connections.

          idlesocket: {configdirectory}/socket/idle
              Unix domain socket that idled listens on.

          ignorereference: 0
              For backwards compatibility with Cyrus 1.5.10 and earlier -- ignore  the  reference
              argument in LIST or LSUB commands.

          imapidlepoll: 60
              The  interval (in seconds) 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.  A value of 0 will disable IDLE.

          imapidresponse: 1
              If  enabled, the server responds to an ID command with a parameter list containing:
              version, vendor, support-url,  os,  os-version,  command,  arguments,  environment.
              Otherwise the server returns NIL.

          imapmagicplus: 0
              Only  list  a restricted set of mailboxes via IMAP by using userid+namespace syntax
              as the authentication/authorization id.  Using userid+ (with  an  empty  namespace)
              will list only subscribed mailboxes.

          imipnotifier: <none>
              Notifyd(8)  method to use for "IMIP" notifications which are based on the RFC 6047.
              If not set, "IMIP" notifications are disabled.

          implicit_owner_rights: lkxa
              The implicit Access Control List (ACL) for the owner of a mailbox.

          @include: <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.

          improved_mboxlist_sort: 0
              If  enabled,  a  special  comparator will be used which will correctly sort mailbox
              names that contain characters such as ' ' and '-'.

              Note that this option SHOULD NOT be  changed  on  a  live  system.   The  mailboxes
              database should be dumped (ctl_mboxlist) before the option is changed, removed, and
              then undumped after changing the  option.   When  not  using  flat  files  for  the
              subscriptions  databases the same has to be done (cyr_dbtool) for each subscription
              database See improved_mboxlist_sort.html.

          internaldate_heuristic: standard
              Mechanism to determine email  internaldates  on  delivery/reconstruct.   "standard"
              uses  time()  when  delivering  a  message, mtime on reconstruct.  "receivedheader"
              looks at the top most Received  header  or  time/mtime  otherwise  Allowed  values:
              standard, receivedheader

          iolog: 0
              Should cyrus output I/O log entries

          ldap_authz: <none>
              SASL authorization ID for the LDAP server

          ldap_base: <empty string>
              Contains the LDAP base dn for the LDAP ptloader module

          ldap_bind_dn: <none>
              Bind  DN  for  the  connection  to  the  LDAP server (simple bind).  Do not use for
              anonymous simple binds

          ldap_deref: never
              Specify how aliases dereferencing is handled during search.

              Allowed values: search, find, always, never

          ldap_domain_base_dn: <empty string>
              Base DN to search for domain name spaces.

          ldap_domain_filter: (&(objectclass=domainrelatedobject)(associateddomain=%s))
              Filter to use searching for domains

          ldap_domain_name_attribute: associateddomain
              The attribute name for domains.

          ldap_domain_scope: sub
              Search scope

              Allowed values: sub, one, base

          ldap_domain_result_attribute: inetdomainbasedn
              Result attribute

          ldap_filter: (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  %D    =  user  dn.   (use  when
              ldap_member_method: 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: <empty string>
              LDAP base dn for ldap_group_filter.

          ldap_group_filter: (cn=%u)
              Specify  a  filter  that  searches for group identifiers.  See ldap_filter for more
              options.

          ldap_group_scope: sub
              Specify search scope for ldap_group_filter.

              Allowed values: sub, one, base

          ldap_id: <none>
              SASL authentication ID for the LDAP server

          ldap_mech: <none>
              SASL mechanism for LDAP authentication

          ldap_user_attribute: <none>
              Specify LDAP attribute to use as canonical user id

          ldap_member_attribute: <none>
              See ldap_member_method.

          ldap_member_base: <empty string>
              LDAP base dn for ldap_member_filter.

          ldap_member_filter: (member=%D)
              Specify a filter  for  "ldap_member_method:  filter".   See  ldap_filter  for  more
              options.

          ldap_member_method: attribute
              Specify   a   group  method.   The  "attribute"  method  retrieves  groups  from  a
              multi-valued attribute specified in ldap_member_attribute.

              The "filter" method uses a filter, specified by ldap_member_filter, to find groups;
              ldap_member_attribute  is  a  single-value  attribute  group name.  Allowed values:
              attribute, filter

          ldap_member_scope: sub
              Specify search scope for ldap_member_filter.

              Allowed values: sub, one, base

          ldap_password: <none>
              Password for the connection to the LDAP server (SASL and simple bind).  Do not  use
              for anonymous simple binds

          ldap_realm: <none>
              SASL realm for LDAP authentication

          ldap_referrals: 0
              Specify whether or not the client should follow referrals.

          ldap_restart: 1
              Specify  whether  or  not  LDAP  I/O operations are automatically restarted if they
              abort prematurely.

          ldap_sasl: 1
              Use SASL for LDAP binds in the LDAP PTS module.

          ldap_sasl_authc: <none>
              Deprecated.  Use ldap_id

          ldap_sasl_authz: <none>
              Deprecated.  Use ldap_authz

          ldap_sasl_mech: <none>
              Deprecated.  Use ldap_mech

          ldap_sasl_password: <none>
              Deprecated.  User ldap_password

          ldap_sasl_realm: <none>
              Deprecated.  Use ldap_realm

          ldap_scope: sub
              Specify search scope.

              Allowed values: sub, one, base

          ldap_servers: ldap://localhost/
              Deprecated.  Use ldap_uri

          ldap_size_limit: 1
              Specify a number of entries for a search request to return.

          ldap_start_tls: 0
              Use transport layer security for ldap:// using STARTTLS. Do  not  use  ldaps://  in
              'ldap_uri' with this option enabled.

          ldap_time_limit: 5
              Specify a number of seconds for a search request to complete.

          ldap_timeout: 5
              Specify a number of seconds a search can take before timing out.

          ldap_ca_dir: <none>
              Path to a directory with CA (Certificate Authority) certificates.

          ldap_ca_file: <none>
              Patch to a file containing CA (Certificate Authority) certificate(s).

          ldap_ciphers: <none>
              List  of  SSL/TLS  ciphers  to  allow.   The  format  of the string is described in
              ciphers(1).

          ldap_client_cert: <none>
              File containing the client certificate.

          ldap_client_key: <none>
              File containing the private client key.

          ldap_verify_peer: 0
              Require and verify server certificate.  If this option is  yes,  you  must  specify
              ldap_ca_file or ldap_ca_dir.

          ldap_tls_cacert_dir: <none>
              Deprecated in favor of ldap_ca_dir.

          ldap_tls_cacert_file: <none>
              Deprecated in favor of ldap_ca_file.

          ldap_tls_cert: <none>
              Deprecated in favor of ldap_client_cert.

          ldap_tls_key: <none>
              Deprecated in favor of ldap_client_key.

          ldap_tls_check_peer: 0
              Deprecated in favor of ldap_verify_peer.

          ldap_tls_ciphers: <none>
              Deprecated in favor of ldap_ciphers.

          ldap_uri: <none>
              Contains a list of the URLs of all the LDAP servers when using the LDAP PTS module.

          ldap_version: 3
              Specify  the  LDAP  protocol  version.   If ldap_start_tls and/or ldap_use_sasl are
              enabled, ldap_version will be automatically set to 3.

          literalminus: 0
              if enabled, CAPABILITIES will reply with LITERAL- rather than LITERAL+ (RFC  7888).
              Doesn't actually size-restrict uploads though

          lmtp_downcase_rcpt: 1
              If  enabled,  lmtpd  will convert the recipient addresses to lowercase (up to a '+'
              character, if present).

          lmtp_fuzzy_mailbox_match: 0
              If enabled, and  the  mailbox  specified  in  the  detail  part  of  the  recipient
              (everything after the '+') does not exist, lmtpd will try to find the closest match
              (ignoring case, ignoring whitespace, falling  back  to  parent)  to  the  specified
              mailbox name.

          lmtp_over_quota_perm_failure: 0
              If  enabled,  lmtpd  returns a permanent failure code when a user's mailbox is over
              quota.  By default, the failure is temporary, causing the MTA to queue the  message
              and retry later.

          lmtp_strict_quota: 0
              If  enabled,  lmtpd returns a failure code when the incoming message will cause the
              user's mailbox to exceed its quota.  By default, the failure won't occur until  the
              mailbox is already over quota.

          lmtp_strict_rfc2821: 1
              By  default,  lmtpd  will  be  strict (per RFC 2821) with regards to which envelope
              addresses are allowed.  If this option is set to  false,  8bit  characters  in  the
              local-part  of  envelope  addresses  are changed to 'X' instead.  This is useful to
              avoid generating backscatter with certain MTAs like Postfix or  Exim  which  accept
              such messages.

          lmtpsocket: {configdirectory}/socket/lmtp
              Unix domain socket that lmtpd listens on, used by deliver(8). This should match the
              path specified in cyrus.conf(5).

          lmtptxn_timeout: 300
              Timeout (in seconds) used during a lmtp transaction to a remote backend (e.g. in  a
              murder  environment).   Can  be  used  to prevent hung lmtpds on proxy hosts when a
              backend server becomes unresponsive during a lmtp transaction.  The default is  300
              - change to zero for infinite.

          loginrealms: <empty string>
              The   list  of  remote  realms  whose  users  may  authenticate  using  cross-realm
              authentication identifiers.  Separate each realm name by a space.   (A  cross-realm
              identity is considered any identity returned by SASL with an "@" in it.).

          loginuseacl: 0
              If  enabled,  any  authentication identity which has a rights on a user's INBOX may
              log in as that user.

          logtimestamps: 0
              Include notations in the protocol telemetry logs indicating the number  of  seconds
              since the last command or response.

          mailbox_default_options: 0
              Default "options" field for the mailbox on create.  You'll want to know what you're
              doing before setting this, but it can apply some default annotations like duplicate
              suppression

          mailbox_initial_flags: <none>
              space-separated  list  of  permanent  flags  which  will  be pre-set in every newly
              created mailbox.  If you know you will require  particular  flag  names  then  this
              avoids  a  possible  race  condition  against  a  client  that fills the entire 128
              available slots.  Default is NULL, which is no  flags.   Example:  $Label1  $Label2
              $Label3 NotSpam Spam

          mailnotifier: <none>
              Notifyd(8)   method   to   use  for  "MAIL"  notifications.   If  not  set,  "MAIL"
              notifications are disabled.

          maxheaderlines: 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

          maxlogins_per_host: 0
              Maximum number of logged in sessions allowed per host, zero means no limit

          maxlogins_per_user: 0
              Maximum number of logged in sessions allowed per user, zero means no limit

          maxmessagesize: 0
              Maximum incoming LMTP message size.  If non-zero, lmtpd will reject messages larger
              than maxmessagesize bytes.  If set to 0, this will allow messages of any size  (the
              default).

          maxquoted: 131072
              Maximum size of a single quoted string for the parser.  Default 128k

          maxword: 131072
              Maximum size of a single word for the parser.  Default 128k

          mboxkey_db: twoskip
              The cyrusdb backend to use for mailbox keys.

              Allowed values: skiplist, twoskip, lmdb

          mboxlist_db: twoskip
              The cyrusdb backend to use for the mailbox list.

              Allowed values: flat, skiplist, sql, twoskip, lmdb

          mboxlist_db_path: <none>
              The   absolute   path  to  the  mailboxes  db  file.   If  not  specified  will  be
              configdirectory/mailboxes.db

          mboxname_lockpath: <none>
              Path to mailbox name lock files (default $conf/lock)

          metapartition_files: <empty string>
              Space-separated list of metadata files to be stored on a metapartition rather  than
              in  the  mailbox  directory  on  a spool partition.  Allowed values: header, index,
              cache, expunge, squat, annotations, lock, dav, archivecache

          metapartition-name: <none>
              The pathname of the metadata  partition  name,  corresponding  to  spool  partition
              partition-name.   For  any  mailbox  residing in a directory on partition-name, the
              metadata files listed in metapartition_files will  be  stored  in  a  corresponding
              directory  on  metapartition-name.    Note  that not every partition-name option is
              required to have  a  corresponding  metapartition-name  option,  so  that  you  can
              selectively choose which spool partitions will have separate metadata partitions.

          mupdate_authname: <none>
              The  SASL  username (Authentication Name) to use when authenticating to the mupdate
              server (if needed).

          mupdate_config: standard
              The configuration of the mupdate servers  in  the  Cyrus  Murder.   The  "standard"
              config  is  one  in  which there are discreet frontend (proxy) and backend servers.
              The "unified" config is one in which a server can be both a frontend  and  backend.
              The "replicated" config is one in which multiple backend servers all share the same
              mailspool, but each have their own  "replicated"  copy  of  mailboxes.db.   Allowed
              values: standard, unified, replicated

          munge8bit: 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_connections_max: 128
              The max number of connections that a mupdate process will allow, this is related to
              the  number  of  file  descriptors  in  the  mupdate  process.   Beyond this number
              connections will be immediately issued a BYE response.

          mupdate_password: <none>
              The SASL password (if needed) to use when authenticating to the mupdate server.

          mupdate_port: 3905
              The port of the mupdate server for the Cyrus Murder

          mupdate_realm: <none>
              The SASL realm (if needed) to use when authenticating to the mupdate server.

          mupdate_retry_delay: 20
              The base time to wait between connection retries to the mupdate server.

          mupdate_server: <none>
              The mupdate server for the Cyrus Murder

          mupdate_username: <empty string>
              The SASL username (Authorization Name) to use when authenticating  to  the  mupdate
              server

          mupdate_workers_max: 50
              The maximum number of mupdate worker threads (overall)

          mupdate_workers_maxspare: 10
              The maximum number of idle mupdate worker threads

          mupdate_workers_minspare: 2
              The minimum number of idle mupdate worker threads

          mupdate_workers_start: 5
              The number of mupdate worker threads to start

          netscapeurl: <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: 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: *
              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: 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: <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: <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: <none>
              Prefix to be prepended to newsgroup names to make the  corresponding  IMAP  mailbox
              names.

          newsrc_db_path: <none>
              The   absolute   path   to   the  newsrc  db  file.   If  not  specified,  will  be
              configdirectory/fetchnews.db

          nntptimeout: 3
              Set the length of the NNTP server's inactivity autologout timer, in  minutes.   The
              minimum value is 3, the default.

          notesmailbox: <none>
              The  top  level mailbox in each user's account which is used to store * Apple-style
              Notes.  Default is blank (disabled)

          notifysocket: {configdirectory}/socket/notify
              Unix domain socket that the mail notification daemon listens on.

          notify_external: <none>
              Path to the external program that notifyd(8) will call to send mail notifications.

              The external program will be called with the following command line options:

                 -c class

                 -p priority

                 -u user

                 -m mailbox

                 And the notification message will be available on stdin.

          partition-name: <none>
              The pathname of the partition name.   At  least  one  partition  pathname  MUST  be
              specified.   If  the  defaultpartition  option  is  used, then its pathname MUST be
              specified.  For example, if the value of the defaultpartion option is  part1,  then
              the partition-part1 field is required.

          outbox_sendlater: 0
              If  enabled,  any  message  with  a  Draft  flag  will  be  sent at the time of its
              INTERNALDATE

          partition_select_mode: freespace-most
              Partition selection mode.

              random (pseudo-)random selection

              freespace-most
                     partition with the most free space (KiB)

              freespace-percent-most
                     partition with the most free space (%)

              freespace-percent-weighted
                     each partition is weighted according to its free space (%);  the  more  free
                     space the partition has, the more chances it has to be selected

              freespace-percent-weighted-delta
                     each  partition  is  weighted  according to its difference of free space (%)
                     compared to the most used partition;  the  more  the  partition  is  lagging
                     behind the most used partition, the more chances it has to be selected

                     Note  that  actually  even  the  most used partition has a few chances to be
                     selected, and those chances increase when other partitions get closer

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

          partition_select_exclude: <none>
              List of partitions to exclude from selection mode.

          partition_select_usage_reinit: 0
              For  a  given  session,  number  of operations (e.g. partition selection) for which
              partitions usage data are cached.

          partition_select_soft_usage_limit: 0
              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.

          plaintextloginpause: 0
              Number  of  seconds  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.)

          plaintextloginalert: <none>
              Message to send to client after a successful plaintext login.

          popexpiretime: -1
              The number of days 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).  "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.

          popminpoll: 0
              Set  the  minimum amount of time the server forces users to wait between successive
              POP logins, in minutes.

          popsubfolders: 0
              Allow access to subfolders of INBOX via POP3 by using  userid+subfolder  syntax  as
              the authentication/authorization id.

          poppollpadding: 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.

          poptimeout: 10
              Set  the  length  of the POP server's inactivity autologout timer, in minutes.  The
              minimum value is 10, the default.

          popuseacl: 0
              Enforce IMAP ACLs in the pop server.  Due to the nature of the POP3  protocol,  the
              only rights which are used by the pop server are 'r', 't', and 's' for the owner of
              the mailbox.  The 'r' right allows the user to open the mailbox  and  list/retrieve
              messages.   The 't' right allows the user to delete messages.  The 's' right allows
              messages retrieved by the user to have the \Seen flag set (only if  popuseimapflags
              is also enabled).

          popuseimapflags: 0
              If  enabled,  the  pop  server  will  set and obey IMAP flags.  Messages having the
              \Deleted flag are ignored as if they do not exist.  Messages that are retrieved  by
              the  client  will have the \Seen flag set.  All messages will have the \Recent flag
              unset.

          postmaster: postmaster
              Username that is used as the 'From' address in rejection MDNs produced by sieve.

          postuser: <empty string>
              Userid used to deliver messages to shared folders.  For example, if  set  to  "bb",
              email  sent to "bb+shared.blah" would be delivered to the "shared.blah" folder.  By
              default, an email address of "+shared.blah" would be used.

          proc_path: <none>
              Path to proc directory.  Default is NULL - must be an absolute path  if  specified.
              If not specified, the path $configdirectory/proc/ will be used.

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

          proxy_compress: 0
              Try to enable protocol-specific compression when performing a client connection  to
              a backend server in the Cyrus Murder.

              Note  that  this should only be necessary over slow network connections.  Also note
              that currently only IMAP and MUPDATE support compression.

          proxy_password: <none>
              The default password to use when authenticating to a backend server  in  the  Cyrus
              Murder.   May  be  overridden  on a host-specific basis using the hostname_password
              option.

          proxy_realm: <none>
              The authentication realm to use when authenticating to  a  backend  server  in  the
              Cyrus Murder

          proxyd_allow_status_referral: 0
              Set  to  true  to  allow  proxyd to issue referrals to clients that support it when
              answering the STATUS command.  This is disabled by default since some clients issue
              many  STATUS  commands  in  a  row,  and  do  not  cache the connections that these
              referrals would cause, thus resulting  in  a  higher  authentication  load  on  the
              respective backend server.

          proxyd_disable_mailbox_referrals: 0
              Set to true to disable the use of mailbox-referrals on the proxy servers.

          proxyservers: <none>
              A  list of users and groups that are allowed to proxy for other users, separated by
              spaces.  Any user listed in this will be allowed to login for any other  user:  use
              with caution.  In a standard murder this option should ONLY be set on backends.  DO
              NOT SET on frontends or things won't work properly.

          pts_module: afskrb
              The PTS module to use.

              Allowed values: afskrb, ldap

          ptloader_sock: <none>
              Unix    domain    socket    that    ptloader    listens    on.     (defaults     to
              configdirectory/ptclient/ptsock)

          ptscache_db: twoskip
              The cyrusdb backend to use for the pts cache.

              Allowed values: skiplist, twoskip, lmdb

          ptscache_db_path: <none>
              The   absolute   path  to  the  ptscache  db  file.   If  not  specified,  will  be
              configdirectory/ptscache.db

          ptscache_timeout: 10800
              The timeout (in seconds) for the PTS cache database  when  using  the  auth_krb_pts
              authorization method (default: 3 hours).

          ptskrb5_convert524: 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: 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: 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: quotalegacy
              The cyrusdb backend to use for quotas.

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

          quota_db_path: <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/

          quotawarn: 90
              The percent of quota utilization over which the server generates warnings.

          quotawarnkb: 0
              The maximum amount of free space (in kB) 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).

          quotawarnmsg: 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).

          reject8bit: 0
              If enabled, lmtpd rejects messages with 8-bit characters in the headers.

          restore_authname: <none>
              The  authentication  used  by  the restore tool when authenticating to an IMAP/sync
              server.

          restore_password: <none>
              The password used by the restore tool when authenticating to an IMAP/sync server.

          restore_realm: <none>
              The authentication realm used  by  the  restore  tool  when  authenticating  to  an
              IMAP/sync server.

          reverseacls: 0
              At  startup  time,  ctl_cyrusdb  -r will check this value and it will either add or
              remove reverse ACL pointers from mailboxes.db

          rfc2046_strict: 0
              If enabled, imapd will be  strict  (per  RFC  2046)  when  matching  MIME  boundary
              strings.  This means that boundaries containing other boundaries as substrings will
              be treated as identical.  Since enabling  this  option  will  break  some  messages
              created  by  Eudora  5.1  (and earlier), it is recommended that it be left disabled
              unless there is good reason to do otherwise.

          rfc2047_utf8: 0
              If enabled, imapd will parse any non-encoded  character  sequence  in  MIME  header
              values as UTF8. This is useful for installations that either advertise the UTF8SMTP
              (RFC 5335) extension or receive mails with improperly escaped UTF-8 byte sequences.
              It  is recommended that this option is left disabled unless there is good reason to
              do otherwise.

          rfc3028_strict: 1
              If enabled, Sieve will be strict (per RFC 3028) with regards to which  headers  are
              allowed  to  be  used  in  address  and envelope tests.  This means that only those
              headers which are defined to contain addresses will be allowed in address tests and
              only  "to"  and  "from"  will  be  allowed  in  envelope tests.  When disabled, ANY
              grammatically correct header will be allowed.

          rss_feedlist_template: <none>
              File containing HTML that will be used as a template for  displaying  the  list  of
              available  RSS  feeds.   A  single  instance  of the variable %RSS_FEEDLIST% should
              appear in the file, which will be replaced by a nested  unordered  list  of  feeds.
              The  toplevel  unordered  list will be tagged with an id of "feed" (<ul id='feed'>)
              which can be used by stylesheet(s) in your template.  The dynamically created  list
              of  feeds  based  on  the HTML template will be accessible at the "/rss" URL on the
              server.

          rss_feeds: *
              A wildmat pattern specifying which mailbox hierarchies should  be  treated  as  RSS
              feeds.   Only mailboxes matching the wildmat will have their messages available via
              RSS.  If not set, a default wildmat of "*" (ALL mailboxes) will be used.

          rss_maxage: 0
              Maximum age (in days) of items to display in an RSS channel.   If  non-zero,  httpd
              will only display items received within the last rss_maxage days.  If set to 0, all
              available items will be displayed (the default).

          rss_maxitems: 0
              Maximum number of items to display in an RSS  channel.   If  non-zero,  httpd  will
              display  no  more  than  the  rss_maxitems  most  recent  items.   If set to 0, all
              available items will be displayed (the default).

          rss_maxsynopsis: 0
              Maximum RSS item synopsis length.  If non-zero, httpd will display no more than the
              first  rss_maxsynopsis  characters  of an item's synopsis.  If set to 0, the entire
              synopsis will be displayed (the default).

          rss_realm: <none>
              The realm to present for HTTP  authentication  of  RSS  feeds.   If  not  set  (the
              default), the value of the "servername" option will be used.

          sasl_auto_transition: 0
              If  enabled, the SASL library will automatically create authentication secrets when
              given a plaintext password.  See the SASL documentation.

          sasl_maximum_layer: 256
              Maximum SSF (security strength factor) that the  server  will  allow  a  client  to
              negotiate.

          sasl_minimum_layer: 0
              The  minimum  SSF  that  the server will allow a client to negotiate.  A value of 1
              requires integrity protection; any higher value requires some amount of encryption.

          sasl_option: 0
              Any SASL option can be set by preceding it with sasl_.   This  file  overrides  the
              SASL configuration file.

          sasl_pwcheck_method: <none>
              The  mechanism  used  by the server to verify plaintext passwords.  Possible values
              include "auxprop", "saslauthd", and "pwcheck".

          search_batchsize: 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_normalisation_max: 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_engine: none
              The indexing engine used to speed up searching.

              Allowed values: none, squat, sphinx, xapian

          search_fuzzy_always: 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: 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
              is  header  indexing  is disabled, headers can still be searched, the searches will
              just be slower.

          search_indexed_db: twoskip
              The cyrusdb backend to use for the search latest indexed uid state.

              Allowed values: flat, skiplist, twoskip, lmdb

          search_maxtime: <none>
              The maximum number of seconds to run a search for before aborting.  Default  of  no
              value means search "forever" until other timeouts.

          search_skipdiacrit: 1
              When searching, should diacriticals be stripped from the search terms.  The default
              is "true", a search for "hav" will match "HÃ¥vard".  This is not RFC 5051 compliant,
              but it backwards compatible, and may be preferred by some sites.

          search_skiphtml: 0
              If  enabled,  HTML  parts  of  messages  are  skipped,  i.e.  not  indexed  and not
              searchable.  Otherwise, they're indexed.

          search_whitespace: 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

          search_snippet_length: 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: <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.list.

          searchpartition-name: <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 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: twoskip
              The cyrusdb backend to use for the seen state.

              Allowed values: flat, skiplist, twoskip, lmdb

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

          serverlist: <none>
              Whitespace separated list of backend server names.  Used for  finding  server  with
              the most available free space for proxying CREATE.

          serverlist_select_mode: 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_usage_reinit: 0
              For a given session, number  of  operations  (e.g.  backend  selection)  for  which
              backend usage data are cached.

          serverlist_select_soft_usage_limit: 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.

          servername: <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.

          serverinfo: 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

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

          sieve_allowreferrals: 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_extensions:  fileinto  reject vacation vacation-seconds imapflags notify envelope
          relational  regex  subaddress  copy  date   index   imap4flags   mailbox   mboxmetadata
          servermetadata variables
              Space-separated  list  of  Sieve  extensions  allowed  to be used in sieve scripts,
              enforced at submission by timsieved(8).  Any previously installed  script  will  be
              unaffected by this option and will continue to execute regardless of the extensions
              used.  This option has no effect on options  that  are  disabled  at  compile  time
              (e.g.,  "regex").   Allowed  values:  fileinto, reject, vacation, vacation-seconds,
              imapflags, notify, include, envelope, body, relational,  regex,  subaddress,  copy,
              date, index, imap4flags, mailbox, mboxmetadata, servermetadata, variables

          sieve_maxscriptsize: 32
              Maximum  size  (in  kilobytes)  any  sieve script can be, enforced at submission by
              timsieved(8).

          sieve_maxscripts: 5
              Maximum number of sieve scripts any  user  may  have,  enforced  at  submission  by
              timsieved(8).

          sieve_utf8fileinto: 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_sasl_send_unsolicited_capability: 0
              If enabled, timsieved will emit a  capability  response  after  a  successful  SASL
              authentication, per draft-martin-managesieve-12.txt .

          sieve_vacation_min_response: 259200 /* 3 days */
              Minimum  time  interval  (in  seconds)  between consecutive vacation responses, per
              draft-ietf-vacation-seconds.txt .

          sieve_vacation_max_response: 7776000 /* 90 days */
              Maximum time interval (in seconds)  between  consecutive  vacation  responses,  per
              draft-ietf-vacation-seconds.txt .

          sievedir: /usr/sieve
              If sieveusehomedir is false, this directory is searched for Sieve scripts.

          sievenotifier: <none>
              Notifyd(8)   method  to  use  for  "SIEVE"  notifications.   If  not  set,  "SIEVE"
              notifications are disabled.

              This method is only used when no method is specified in the script.

          sieveusehomedir: 0
              If enabled,  lmtpd  will  look  for  Sieve  scripts  in  user's  home  directories:
              ~user/.sieve.

          anysievefolder: 0
              It  must  be  "yes"  in  order  to  permit  the autocreation of any INBOX subfolder
              requested by a sieve filter, through the "fileinto" action. (default = no)

          singleinstancestore: 1
              If enabled, imapd, lmtpd and nntpd attempt to only write one copy of a message  per
              partition and create hard links, resulting in a potentially large disk savings.

          skiplist_always_checkpoint: 1
              If  enabled,  this  option forces the skiplist cyrusdb backend to always checkpoint
              when doing a recovery.  This causes slightly more IO, but on the other  hand  leads
              to more efficient databases, and the entire file is already "hot".

          skiplist_unsafe: 0
              If  enabled,  this option forces the skiplist cyrusdb backend to not sync writes to
              the disk.  Enabling this option is NOT RECOMMENDED.

          soft_noauth: 1
              If enabled, lmtpd returns temporary failures if the client  does  not  successfully
              authenticate.   Otherwise  lmtpd  returns  permanent  failures (causing the mail to
              bounce immediately).

          sortcache_db: twoskip
              The cyrusdb backend to use for  caching  sort  results  (currently  only  used  for
              xconvmultisort) Allowed values: skiplist, twoskip, lmdb

          specialuse_extra: <none>
              Whitespace  separated  list  of  extra  special-use attributes that can be set on a
              mailbox. RFC 6154 currently lists what special-use  attributes  can  be  set.  This
              allows extending that list in the future or adding your own if needed.

          specialusealways: 0
              If  enabled,  this  option  causes LIST and LSUB output to always include the XLIST
              "special-use" flags

          sphinx_text_excludes_odd_headers: 0
              If enabled, Sphinx will perform a TEXT search as if it matches FROM, TO, CC, BCC or
              SUBJECT  but  not any other headers.  This is contrary to the RFC but a more useful
              behaviour for most users.  Default: disabled.

          sphinx_socket: {configdirectory}/socket/sphinx
              Unix domain socket that the Sphinx searchd daemons listens on.

          sphinx_pidfile: /var/run/sphinx.pid
              File where the Sphinx searchd daemon writes its pid.

          sql_database: <none>
              Name of the database which contains the cyrusdb table(s).

          sql_engine: <none>
              Name of the SQL engine to use.

              Allowed values: mysql, pgsql, sqlite

          sql_hostnames: <empty string>
              Comma separated list of SQL servers (in host[:port] format).

          sql_passwd: <none>
              Password to use for authentication to the SQL server.

          sql_user: <none>
              Username to use for authentication to the SQL server.

          sql_usessl: 0
              If enabled, a secure connection will be made to the SQL server.

          srvtab: <empty string>
              The pathname of srvtab file containing the server's private key.   This  option  is
              passed to the SASL library and overrides its default setting.

          submitservers: <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: flat
              The cyrusdb backend to use for the subscriptions list.

              Allowed values: flat, skiplist, twoskip, lmdb

          suppress_capabilities: <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.

          statuscache: 0
              Enable/disable the imap status cache.

          statuscache_db: twoskip
              The cyrusdb backend to use for the imap status cache.

              Allowed values: skiplist, sql, twoskip, lmdb

          statuscache_db_path: <none>
              The absolute  path  to  the  statuscache  db  file.   If  not  specified,  will  be
              configdirectory/statuscache.db

          sync_authname: <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: 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_host: <none>
              Name of the host (replica running sync_server(8)) to which replication actions will
              be  sent  by  sync_client(8).   Prefix  with  a channel name to only apply for that
              channel

          sync_log: 0
              Enable replication action logging by lmtpd(8), imapd(8),  pop3d(8),  and  nntpd(8).
              The   log  {configdirectory}/sync/log  is  used  by  sync_client(8)  for  "rolling"
              replication.

          sync_log_chain: 0
              Enable replication action logging by sync_server  as  well,  allowing  chaining  of
              replicas.  Use this on 'B' for A => B => C replication layout

          sync_log_channels: <none>
              If specified, log all events to multiple log files in directories specified by each
              "channel".  Each channel can then be processed  separately,  such  as  by  multiple
              sync_client(8)s  in a mesh replication scheme, or by squatter(8) for rolling search
              index updates.

              You can use "" (the two-character string  U+22  U+22)  to  mean  the  default  sync
              channel.

          sync_log_unsuppressable_channels: 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: <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: <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: <none>
              The authentication realm to use when authenticating to a sync server.  Prefix  with
              a channel name to only apply for that channel

          sync_repeat_interval: 1
              Minimum interval (in seconds) between replication runs in rolling replication mode.
              If a replication run takes longer than this time, we  repeat  immediately.   Prefix
              with a channel name to only apply for that channel

          sync_shutdown_file: <none>
              Simple  latch  used  to  tell  sync_client(8)  that it should shut down at the next
              opportunity. Safer than sending  signals  to  running  processes.   Prefix  with  a
              channel name to only apply for that channel

          sync_timeout: 1800
              Number  of  seconds  to wait for a response before returning a timeout failure when
              talking to a replication peer (client or server).

          sync_try_imap: 1
              Whether sync_client should try to perform an IMAP connection before falling back to
              csync.   If  this  is  set to "no", sync_client will only use csync.  Prefix with a
              channel name to apply only for that channel

          syslog_prefix: <none>
              String to be prepended to the process name in syslog entries.

          syslog_facility: <none>
              Configure a syslog facility.  The default is  whatever  is  compiled  in.   Allowed
              values are: DAEMON, MAIL, NEWS, USER, and LOCAL0 through to LOCAL7

          tcp_keepalive: 0
              Enable keepalive on TCP connections

          tcp_keepalive_cnt: 0
              Number  of  TCP keepalive probes to send before declaring the connection dead (0 ==
              system default)

          tcp_keepalive_idle: 0
              Number of seconds a connection must be idle before keepalive probes are sent (0  ==
              system default)

          tcp_keepalive_intvl: 0
              Number of seconds between keepalive probes (0 == system default)

          temp_path: /tmp
              The pathname to store temporary files in

          telemetry_bysessionid: 0
              If true, log by sessionid instead of PID for telemetry

          timeout: 32
              The  length  of  the  IMAP  server's  inactivity autologout timer, in minutes.  The
              minimum value is 30.  The default is 32 to allow a bit of leeway for  clients  that
              try to NOOP every 30 minutes.

          imapidletimeout: 0
              Timeout  for  idling clients (RFC 2177) in minutes. If set to zero (the default) or
              less, the value of "timeout" will be used instead.

          tls_ca_file: <none>
              Deprecated in favor of tls_client_ca_file.

          tls_ca_path: <none>
              Deprecated in favor of tls_client_ca_dir.

          tlscache_db: twoskip
              Deprecated in favor of tls_sessions_db.

          tlscache_db_path: <none>
              Deprecated in favor of tls_sessions_db_path.

          tls_cert_file: <none>
              Deprecated in favor of tls_server_cert.

          tls_cipher_list: DEFAULT
              Deprecated in favor of tls_ciphers.

          tls_ciphers: DEFAULT
              The list of SSL/TLS ciphers to allow.  The format of the string (and definition  of
              "DEFAULT") is described in ciphers(1).

              See also Mozilla's server-side TLS recommendations:

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

          tls_client_ca_dir: <none>
              Path  to  a  directory  containing  the  CA  certificates used to verify client SSL
              certificates used for authentication.

          tls_client_ca_file: <none>
              Path to a  file  containing  the  CA  certificate(s)  used  to  verify  client  SSL
              certificates used for authentication.

          tls_client_cert: <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: optional
              Disable  ("off"), allow ("optional", default) or require ("require") the use of SSL
              certificates by clients to authenticate themselves.  Allowed values: off, optional,
              require

          tls_client_key: <none>
              File  containing  the  private  key belonging to the tls_client_cert certificate. A
              value  of  "disabled"  will  disable  this  server's   use   of   certificate-based
              authentication.

          tls_eccurve: prime256v1
              The  elliptic curve used for ECDHE. Default is NIST Suite B prime256.  See 'openssl
              ecparam -list_curves' for possible values.

          tls_key_file: <none>
              Deprecated in favor of tls_server_key.

          tls_required: 0
              If enabled, require a TLS/SSL encryption  layer  to  be  negotiated  prior  to  ANY
              authentication mechanisms being advertised or allowed.

          tls_prefer_server_ciphers: 0
              Prefer the ciphers on the server side instead of client side.

          tls_server_ca_dir: <none>
              Path  to  a directory with CA certificates used to verify certificates offered when
              this server connects to other servers. This directory must have filenames with  the
              hashed value of the certificates (see openssl(1)).

          tls_server_ca_file: <none>
              Path  to a file containing CA certificates used to verify certificates offered when
              this server connects to other servers.

          tls_server_cert: <none>
              File containing the certificate presented to clients.

          tls_server_key: <none>
              File containing the private key belonging to the certificate in tls_server_cert.

          tls_sessions_db: twoskip
              The cyrusdb backend to use for the TLS cache.

              Allowed values: skiplist, sql, twoskip, lmdb

          tls_sessions_db_path: <none>
              The absolute path  to  the  TLS  sessions  db  file.  If  not  specified,  will  be
              configdirectory/tls_sessions.db

          tls_session_timeout: 1440
              The  length of time (in minutes) that a TLS session will be cached for later reuse.
              The maximum value is 1440 (24 hours), the default.   A  value  of  0  will  disable
              session caching.

          tls_versions: tls1_0 tls1_1 tls1_2
              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.

          uidl_format: cyrus
              Choose  the  format  for  UIDLs  in  pop3.  Possible values are "uidonly", "cyrus",
              "dovecot" and "courier".  "uidonly" forces the  old  default  of  UID,  "cyrus"  is
              UIDVALIDITY.UID.   Dovecot  is  8  digits  of  leading  hex  (lower  case) each UID
              UIDVALIDITY. Courier is UIDVALIDITY-UID.  Allowed values: uidonly, cyrus,  dovecot,
              courier

          umask: 077
              The umask value used by various Cyrus IMAP programs.

          userdeny_db: flat
              The cyrusdb backend to use for the user access list.

              Allowed values: flat, skiplist, sql, twoskip, lmdb

          userdeny_db_path: <none>
              The   absolute   path  to  the  userdeny  db  file.   If  not  specified,  will  be
              configdirectory/user_deny.db

          username_tolower: 1
              Convert usernames to all lowercase before  login/authentication.   This  is  useful
              with  authentication  backends  which  ignore case during username lookups (such as
              LDAP).

          userprefix: Other Users
              If using the alternate IMAP namespace, the prefix for the  other  users  namespace.
              The hierarchy delimiter will be automatically appended.

          unix_group_enable: 1
              Should  we  look  up groups when using auth_unix (disable this if you are not using
              groups in ACLs for your IMAP server, and you are using  auth_unix  with  a  backend
              (such as LDAP) that can make getgrent() calls very slow)

          unixhierarchysep: 1
              Use  the  UNIX  separator character '/' for delimiting levels of mailbox hierarchy.
              Turn off to use the netnews separator character '.'. Note  that  with  the  newnews
              separator,  no  dots  may occur in mailbox names.  The default switched in 3.0 from
              off to on.

          virtdomains: off
              Enable virtual domain support.  If enabled, the user's domain will be determined by
              splitting a fully qualified userid at the last '@' or '%' symbol.  If the userid is
              unqualified, and the virtdomains option is set to "on", then  the  domain  will  be
              determined  by  doing  a  reverse  lookup on the IP address of the incoming network
              interface, otherwise the user is assumed to be in  the  default  domain  (if  set).
              Allowed values: off, userid, on

          xbackup_enabled: 0
              Enable  support  for the XBACKUP command in imapd.  If enabled, admin users can use
              this command to provoke a replication  of  specified  users  to  the  named  backup
              channel.

          xlist-flag: <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.)

          lmtp_catchall_mailbox: <none>
              Mail  sent  to mailboxes which do not exist, will be delivered to this user.  NOTE:
              This must be an existing local user name with an INBOX, NOT an email address!

          zoneinfo_db: twoskip
              The cyrusdb backend to use for zoneinfo.

              Allowed values: flat, skiplist, twoskip, lmdb

          zoneinfo_db_path: <none>
              The  absolute  path  to  the  zoneinfo  db  file.   If  not  specified,   will   be
              configdirectory/zoneinfo.db

          object_storage_enabled: 0
              Is Object storage enabled for this server.  You also need to have archiving enabled
              and archivepartition for the mailbox.  Only email files will be  stored  on  object
              Storage archive partition will be used to store any other files

          object_storage_dummy_spool: <none>
              Dummy  object  storage  spool;  this  is for test only.  Spool where user directory
              (container) will be created to store all emails in a flat structure

          openio_namespace: <none>
              The OpenIO namespace used to store archived email messages. A namespace  identifies
              the  physical  platform  cyrus must contact. This directive is used by the OpenIO's
              SDK to locate its platform entry point.

          openio_account: <none>
              The OpenIO account used to account for stored emails. Accounts are unique in  their
              namespace. They provides virtual partitions, with quotas and QoS features.

          openio_rawx_timeout: 30
              The OpenIO timeout to query to the RAWX services (default 30 sec).

          openio_proxy_timeout: 5
              The OpenIO timeout to query to the PROXY services (default 5 sec).

          openio_autocreate: 0
              Allow  the  OpenIO  SDK  to  autocreate containers. Mainly destined to be turned on
              development environments. In production, the container should have been provisioned
              with the mailboxes.

          openio_verbosity: <none>
              Sets  the  logging  verbosity  of the OpenIO's internal behavior. Admissible values
              are: "warning", "notice", "info", "debug", "trace", "quiet".  The default verbosity
              is  "warning". Set to "notice" for a few lines on a per-client basis. Set to "info"
              for a few lines on a per-request basis. Set to "debug" Set to "trace"  to  activate
              the  underlying  libcurl  debug  output.  Enabling a verbosity higher to equal than
              "debug" requires the cyrus to be set in  debug  mode.  The  special  "quiet"  value
              disables all kinds of logging at the GLib level.

          caringo_hostname: <none>
              The  Caringo  hostname used to store archived email messages. A hostname identifies
              the physical platform cyrus must contact. This directive is used by  the  Caringo's
              SDK  (CastorSDK: Caringo Simple Content Storage Protocol (SCSP) on HTTP 1.1 using a
              RESTful architecture

          caringo_port: 80
              The port of the caringo server (caringo_hostname); default is 80.

          fastmailsharing: 0
              If enabled, use FastMail style sharing (oldschool full server paths)

SEE ALSO

          imapd(8), pop3d(8), nntpd(8), lmtpd(8), httpd(8), timsieved(8),  idled(8),  notifyd(8),
          deliver(8), master(8), ciphers(1)

AUTHOR

       The Cyrus Team

COPYRIGHT

       1993-2017, The Cyrus Team