## ## Mailbox locations and namespaces ## # Location for users' mailboxes. The default is empty, which means that Dovecot # tries to find the mailboxes automatically. This won't work if the user # doesn't yet have any mail, so you should explicitly tell Dovecot the full # location. # # If you're using mbox, giving a path to the INBOX file (eg. /var/mail/%u) # isn't enough. You'll also need to tell Dovecot where the other mailboxes are # kept. This is called the "root mail directory", and it must be the first # path given in the mail_location setting. # # There are a few special variables you can use, eg.: # # %u - username # %n - user part in user@domain, same as %u if there's no domain # %d - domain part in user@domain, empty if there's no domain # %h - home directory # # See doc/wiki/Variables.txt for full list. Some examples: # # mail_location = maildir:~/Maildir # mail_location = mbox:~/mail:INBOX=/var/mail/%u # mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n # # # # mail_location = mbox:~/mail:INBOX=/var/mail/%u # mail_location = # mail_location = mbox:~/mail:INBOX=/var/mail/%u mail_location = mdbox:~/mdbox # If you need to set multiple mailbox locations or want to change default # namespace settings, you can do it by defining namespace sections. # # You can have private, shared and public namespaces. Private namespaces # are for user's personal mails. Shared namespaces are for accessing other # users' mailboxes that have been shared. Public namespaces are for shared # mailboxes that are managed by sysadmin. If you create any shared or public # namespaces you'll typically want to enable ACL plugin also, otherwise all # users can access all the shared mailboxes, assuming they have permissions # on filesystem level to do so. namespace inbox { # Namespace type: private, shared or public type = private # Hierarchy separator to use. You should use the same separator for all # namespaces or some clients get confused. '/' is usually a good one. # The default however depends on the underlying mail storage format. #separator = # Prefix required to access this namespace. This needs to be different for # all namespaces. For example "Public/". #prefix = # Physical location of the mailbox. This is in same format as # mail_location, which is also the default for it. #location = # There can be only one INBOX, and this setting defines which namespace # has it. inbox = yes # If namespace is hidden, it's not advertised to clients via NAMESPACE # extension. You'll most likely also want to set list=no. This is mostly # useful when converting from another server with different namespaces which # you want to deprecate but still keep working. For example you can create # hidden namespaces with prefixes "~/mail/", "~%u/mail/" and "mail/". hidden = no # Show the mailboxes under this namespace with LIST command. This makes the # namespace visible for clients that don't support NAMESPACE extension. # "children" value lists child mailboxes, but hides the namespace prefix. list = yes # Namespace handles its own subscriptions. If set to "no", the parent # namespace handles them (empty prefix should always have this as "yes") subscriptions = yes } namespace local { type = private separator = / prefix = Maildir/ location = maildir:~/Maildir inbox = no hidden = no list = yes subscriptions = no } # Example shared namespace configuration namespace { type = shared separator = / # Mailboxes are visible under "shared/user@domain/" # %%n, %%d and %%u are expanded to the destination user. prefix = shared/%%u/ # Mail location for other users' mailboxes. Note that %variables and ~/ # expands to the logged in user's data. %%n, %%d, %%u and %%h expand to the # destination user's data. #location = maildir:%%h/Maildir:INDEX=~/Maildir/shared/%%u location = mdbox:%%h/mdbox/ # Use the default namespace for saving subscriptions. subscriptions = no # List the shared/ namespace only if there are visible shared mailboxes. list = children } # Should shared INBOX be visible as "shared/user" or "shared/user/INBOX"? #mail_shared_explicit_inbox = yes # System user and group used to access mails. If you use multiple, userdb # can override these by returning uid or gid fields. You can use either numbers # or names. #mail_uid = #mail_gid = # Group to enable temporarily for privileged operations. Currently this is # used only with INBOX when either its initial creation or dotlocking fails. # Typically this is set to "mail" to give access to /var/mail. #mail_privileged_group = # Grant access to these supplementary groups for mail processes. Typically # these are used to set up access to shared mailboxes. Note that it may be # dangerous to set these if users can create symlinks (e.g. if "mail" group is # set here, ln -s /var/mail ~/mail/var could allow a user to delete others' # mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it). mail_access_groups = mail # Allow full filesystem access to clients. There's no access checks other than # what the operating system does for the active UID/GID. It works with both # maildir and mboxes, allowing you to prefix mailboxes names with eg. /path/ # or ~user/. #mail_full_filesystem_access = no ## ## Mail processes ## # Don't use mmap() at all. This is required if you store indexes to shared # filesystems (NFS or clustered filesystem). #mmap_disable = no # Rely on O_EXCL to work when creating dotlock files. NFS supports O_EXCL # since version 3, so this should be safe to use nowadays by default. #dotlock_use_excl = yes # When to use fsync() or fdatasync() calls: # optimized (default): Whenever necessary to avoid losing important data # always: Useful with e.g. NFS when write()s are delayed # never: Never use it (best performance, but crashes can lose data) #mail_fsync = optimized # Mail storage exists in NFS. Set this to yes to make Dovecot flush NFS caches # whenever needed. If you're using only a single mail server this isn't needed. #mail_nfs_storage = no # Mail index files also exist in NFS. Setting this to yes requires # mmap_disable=yes and fsync_disable=no. #mail_nfs_index = no # Locking method for index files. Alternatives are fcntl, flock and dotlock. # Dotlocking uses some tricks which may create more disk I/O than other locking # methods. NFS users: flock doesn't work, remember to change mmap_disable. #lock_method = fcntl # Directory in which LDA/LMTP temporarily stores incoming mails >128 kB. #mail_temp_dir = /tmp # Valid UID range for users, defaults to 500 and above. This is mostly # to make sure that users can't log in as daemons or other system users. # Note that denying root logins is hardcoded to dovecot binary and can't # be done even if first_valid_uid is set to 0. #first_valid_uid = 500 #last_valid_uid = 0 # Valid GID range for users, defaults to non-root/wheel. Users having # non-valid GID as primary group ID aren't allowed to log in. If user # belongs to supplementary groups with non-valid GIDs, those groups are # not set. #first_valid_gid = 1 #last_valid_gid = 0 # Maximum allowed length for mail keyword name. It's only forced when trying # to create new keywords. #mail_max_keyword_length = 50 # ':' separated list of directories under which chrooting is allowed for mail # processes (ie. /var/mail will allow chrooting to /var/mail/foo/bar too). # This setting doesn't affect login_chroot, mail_chroot or auth chroot # settings. If this setting is empty, "/./" in home dirs are ignored. # WARNING: Never add directories here which local users can modify, that # may lead to root exploit. Usually this should be done only if you don't # allow shell access for users. #valid_chroot_dirs = # Default chroot directory for mail processes. This can be overridden for # specific users in user database by giving /./ in user's home directory # (eg. /home/./user chroots into /home). Note that usually there is no real # need to do chrooting, Dovecot doesn't allow users to access files outside # their mail directory anyway. If your home directories are prefixed with # the chroot directory, append "/." to mail_chroot. #mail_chroot = # UNIX socket path to master authentication server to find users. # This is used by imap (for shared users) and lda. auth_socket_path = /var/run/dovecot/auth-userdb # Directory where to look up mail plugins. #mail_plugin_dir = /usr/lib/dovecot/modules # Space separated list of plugins to load for all services. Plugins specific to # IMAP, LDA, etc. are added to this list in their own .conf files. mail_plugins = acl ## ## Mailbox handling optimizations ## # The minimum number of mails in a mailbox before updates are done to cache # file. This allows optimizing Dovecot's behavior to do less disk writes at # the cost of more disk reads. #mail_cache_min_mail_count = 0 # When IDLE command is running, mailbox is checked once in a while to see if # there are any new mails or other changes. This setting defines the minimum # time to wait between those checks. Dovecot can also use dnotify, inotify and # kqueue to find out immediately when changes occur. #mailbox_idle_check_interval = 30 secs # Save mails with CR+LF instead of plain LF. This makes sending those mails # take less CPU, especially with sendfile() syscall with Linux and FreeBSD. # But it also creates a bit more disk I/O which may just make it slower. # Also note that if other software reads the mboxes/maildirs, they may handle # the extra CRs wrong and cause problems. #mail_save_crlf = no # Max number of mails to keep open and prefetch to memory. This only works with # some mailbox formats and/or operating systems. #mail_prefetch_count = 0 # How often to scan for stale temporary files and delete them (0 = never). # These should exist only after Dovecot dies in the middle of saving mails. #mail_temp_scan_interval = 1w ## ## Maildir-specific settings ## # By default LIST command returns all entries in maildir beginning with a dot. # Enabling this option makes Dovecot return only entries which are directories. # This is done by stat()ing each entry, so it causes more disk I/O. # (For systems setting struct dirent->d_type, this check is free and it's # done always regardless of this setting) #maildir_stat_dirs = no # When copying a message, do it with hard links whenever possible. This makes # the performance much better, and it's unlikely to have any side effects. #maildir_copy_with_hardlinks = yes # Assume Dovecot is the only MUA accessing Maildir: Scan cur/ directory only # when its mtime changes unexpectedly or when we can't find the mail otherwise. #maildir_very_dirty_syncs = no # If enabled, Dovecot doesn't use the S= in the Maildir filenames for # getting the mail's physical size, except when recalculating Maildir++ quota. # This can be useful in systems where a lot of the Maildir filenames have a # broken size. The performance hit for enabling this is very small. #maildir_broken_filename_sizes = no ## ## mbox-specific settings ## # Which locking methods to use for locking mbox. There are four available: # dotlock: Create .lock file. This is the oldest and most NFS-safe # solution. If you want to use /var/mail/ like directory, the users # will need write access to that directory. # dotlock_try: Same as dotlock, but if it fails because of permissions or # because there isn't enough disk space, just skip it. # fcntl : Use this if possible. Works with NFS too if lockd is used. # flock : May not exist in all systems. Doesn't work with NFS. # lockf : May not exist in all systems. Doesn't work with NFS. # # You can use multiple locking methods; if you do the order they're declared # in is important to avoid deadlocks if other MTAs/MUAs are using multiple # locking methods as well. Some operating systems don't allow using some of # them simultaneously. #mbox_read_locks = fcntl #mbox_write_locks = dotlock fcntl # Maximum time to wait for lock (all of them) before aborting. #mbox_lock_timeout = 5 mins # If dotlock exists but the mailbox isn't modified in any way, override the # lock file after this much time. #mbox_dotlock_change_timeout = 2 mins # When mbox changes unexpectedly we have to fully read it to find out what # changed. If the mbox is large this can take a long time. Since the change # is usually just a newly appended mail, it'd be faster to simply read the # new mails. If this setting is enabled, Dovecot does this but still safely # fallbacks to re-reading the whole mbox file whenever something in mbox isn't # how it's expected to be. The only real downside to this setting is that if # some other MUA changes message flags, Dovecot doesn't notice it immediately. # Note that a full sync is done with SELECT, EXAMINE, EXPUNGE and CHECK # commands. #mbox_dirty_syncs = yes # Like mbox_dirty_syncs, but don't do full syncs even with SELECT, EXAMINE, # EXPUNGE or CHECK commands. If this is set, mbox_dirty_syncs is ignored. #mbox_very_dirty_syncs = no # Delay writing mbox headers until doing a full write sync (EXPUNGE and CHECK # commands and when closing the mailbox). This is especially useful for POP3 # where clients often delete all mails. The downside is that our changes # aren't immediately visible to other MUAs. #mbox_lazy_writes = yes # If mbox size is smaller than this (e.g. 100k), don't write index files. # If an index file already exists it's still read, just not updated. #mbox_min_index_size = 0 # Mail header selection algorithm to use for MD5 POP3 UIDLs when # pop3_uidl_format=%m. For backwards compatibility we use apop3d inspired # algorithm, but it fails if the first Received: header isn't unique in all # mails. An alternative algorithm is "all" that selects all headers. #mbox_md5 = apop3d ## ## mdbox-specific settings ## # Maximum dbox file size until it's rotated. #mdbox_rotate_size = 2M # Maximum dbox file age until it's rotated. Typically in days. Day begins # from midnight, so 1d = today, 2d = yesterday, etc. 0 = check disabled. #mdbox_rotate_interval = 0 # When creating new mdbox files, immediately preallocate their size to # mdbox_rotate_size. This setting currently works only in Linux with some # filesystems (ext4, xfs). #mdbox_preallocate_space = no ## ## Mail attachments ## # sdbox and mdbox support saving mail attachments to external files, which # also allows single instance storage for them. Other backends don't support # this for now. # WARNING: This feature hasn't been tested much yet. Use at your own risk. # Directory root where to store mail attachments. Disabled, if empty. #mail_attachment_dir = # Attachments smaller than this aren't saved externally. It's also possible to # write a plugin to disable saving specific attachments externally. #mail_attachment_min_size = 128k # Filesystem backend to use for saving attachments: # posix : No SiS done by Dovecot (but this might help FS's own deduplication) # sis posix : SiS with immediate byte-by-byte comparison during saving # sis-queue posix : SiS with delayed comparison and deduplication #mail_attachment_fs = sis posix # Hash format to use in attachment filenames. You can add any text and # variables: %{md4}, %{md5}, %{sha1}, %{sha256}, %{sha512}, %{size}. # Variables can be truncated, e.g. %{sha256:80} returns only first 80 bits #mail_attachment_hash = %{sha1}