---
name: "doveadm-deduplicate"
section: "1"
platform: "linux"
package: "dovecot"
version: "2.4.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/doveadm-deduplicate"
---

# doveadm-deduplicate(1)

Expunge duplicate messages

## NAME

**doveadm-deduplicate** - Expunge duplicate messages

## SYNOPSIS

**doveadm** \[*GLOBAL OPTIONS*\] **deduplicate** \[**-u** *user* \| **-A** \| **-F** *file* \| **--no-userdb-lookup**\] \[**-S** *socket\_path*\] \[**-m**\] *search\_query*

## DESCRIPTION

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)](/doveadm/1.md) will delete the newest duplicated messages from the mailbox and keep the oldest.

Deduplication across multiple mailboxes is not supported.

## GLOBAL OPTIONS

Global [doveadm(1)](/doveadm/1.md) *options*:

- **-D**

  Enables *verbosity* and debug messages.

- **-O**

  Do not read any config file, just use defaults. The **dovecot\_storage\_version** setting defaults to the latest version, but can be overridden with **-o**.

- **-k**

  Preserve entire environment for doveadm, not just **import\_environment** setting.

- **-v**

  Enables verbosity, including progress counter.

- **-i** *instance-name*

  If using multiple Dovecot instances, choose the config file based on this instance name.

  See **instance\_name** setting for more information.

- **-c** *config-file*

  Read configuration from the given *config-file*. By default it first reads config socket, and then falls back to */etc/dovecot/dovecot.conf*. You can also point this to config socket of some instance running compatible version.

- **-o** *setting***=***value*

  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.

## OPTIONS

- **-A**

  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 **userdb\_sql\_iterate\_query** setting setting matches your database layout.

  When using the LDAP userdb module, make sure that the **userdb\_fields** setting and **userdb\_ldap\_iterate\_fields** setting settings match your LDAP schema. Otherwise [doveadm(1)](/doveadm/1.md) will be unable to iterate over all users.

- **-F** *file*

  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.

- **--no-userdb-lookup**

  Do not perform userdb lookup. Use the **USER** environment variable to specify the username.

- **-m**

  if the **-m** option is given, [doveadm(1)](/doveadm/1.md) will deduplicate by Message-Id header. By default deduplication will be done by message GUIDs.

- **-S** *socket\_path*

  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)](/doveadm/1.md) mail commands through the given socket.

- **-u** *user/mask*

  Run the *command* only for the given *user*. It's also possible to use '**\***' and '**?**' wildcards (e.g. -u \*@example.org).

## ARGUMENTS

*search\_query*

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)](/doveadm-search-query/7.md) for details.

## EXAMPLE

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
```

## REPORTING BUGS

Report bugs, including *doveconf -n* output, to the Dovecot Mailing List *⟨dovecot@dovecot.org⟩*. Information about reporting bugs is available at: *⟨https://dovecot.org/bugreport.html⟩*

## SEE ALSO

[doveadm(1)](/doveadm/1.md), [doveadm-import(1)](/doveadm-import/1.md)