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doveadm-deduplicate - expunge duplicate messages


doveadm [-Dv] deduplicate [-u user|-A|-F file] [-S socket_path] [-m] search_query


This command is used to expunge duplicated messages in mailboxes. doveadm deduplicate is mainly useful to revert some (more or less) accidental duplication of messages, e.g. after doveadm copy or doveadm import. doveadm(1) will delete the newest duplicated messages from the mailbox and keep the oldest.
Deduplication across multiple mailboxes is not supported.


Global doveadm(1) options:

Enables verbosity and debug messages.
Overrides the configuration setting from /etc/dovecot/dovecot.conf and from the userdb with the given value. In order to override multiple settings, the -o option may be specified multiple times.
Enables verbosity, including progress counter.

Command specific options:

If the -A option is present, the command will be performed for all users. Using this option in combination with system users from userdb { driver = passwd } is not recommended, because it contains also users with a lower UID than the one configured with the first_valid_uid setting.

When the SQL userdb module is used make sure that the iterate_query setting in /etc/dovecot/dovecot-sql.conf.ext matches your database layout. When using the LDAP userdb module, make sure that the iterate_attrs and iterate_filter settings in /etc/dovecot/dovecot-ldap.conf.ext match your LDAP schema. Otherwise doveadm(1) will be unable to iterate over all users.

Execute the command for all the users in the file. This is similar to the -A option, but instead of getting the list of users from the userdb, they are read from the given file. The file contains one username per line.
The option's argument is either an absolute path to a local UNIX domain socket, or a hostname and port (hostname:port), in order to connect a remote host via a TCP socket.

This allows an administrator to execute doveadm(1) mail commands through the given socket.

if the -m option is given, doveadm(1) will deduplicate by Message-Id header. By default deduplication will be done by message GUIDs.
Run the command only for the given user. It's also possible to use '*' and '?' wildcards (e.g. -u *
When neither the -A option, nor the -F file option, nor the -u user was specified, the command will be executed with the environment of the currently logged in user.


expunge duplicates found from messages matching the given search query. Typically a search query like 'mailbox mailbox_name OR mailbox other_box' will be sufficient. See doveadm-search-query(7) for details.


This example shows how to list and expunge duplicate messages from a mailbox.

doveadm -f table fetch -u jane 'guid uid' mailbox a_Box | sort
guid                             uid
8aad0f0a30169f4bea620000ca356bad 18751
8aad0f0a30169f4bea620000ca356bad 18756
923e301ab9219b4b4f440000ca356bad 18748
923e301ab9219b4b4f440000ca356bad 18753
doveadm deduplicate -u jane mailbox a_Box
doveadm -f table fetch -u jane 'guid uid' mailbox a_Box | sort
guid                             uid
8aad0f0a30169f4bea620000ca356bad 18751
923e301ab9219b4b4f440000ca356bad 18748
a7999e1530739c4bd26d0000ca356bad 18749


Report bugs, including doveconf -n output, to the Dovecot Mailing List <>. Information about reporting bugs is available at:


doveadm(1), doveadm-copy(1), doveadm-fetch(1), doveadm-import(1), doveadm-search-query(7)

2015-05-09 Dovecot v2.3