# Mailbox sharing (Sharing IMAP folder with other users)

> Since iRedMail-`0.7.0`, mailbox sharing related settings are configured in
> Dovecot but not enabled, what you need to do is enabling "acl" plugin as
> mentioned below.

> Since iRedMail-`0.9.0`, mailbox sharing are enabled by default, you don't need
> to modify any config file.

> Do not mistake "shared folders" for "public folders". For shared folders,
> users must select which folder they want to share and with who, using an
> interface, like IMAP command line or the ones available with Roundcube
> webmail or SOGo and SOGo connectors.

## Enable mailbox sharing

To enable mailbox sharing, please make sure you have plugin `acl` enabled
in Dovecot config file `/etc/dovecot/dovecot.conf` like below:

* For Dovecot-1.2:
```
# Part of file: /etc/dovecot/dovecot.conf

protocol lda {
    mail_plugins = ... acl
}

protocol imap {
    mail_plugins = ... acl imap_acl
}
```

* For Dovecot-2.x:
```
# Part of file: /etc/dovecot/dovecot.conf

mail_plugins = ... acl

protocol imap {
    mail_plugins = ... imap_acl
}
```

Restarting Dovecot service is required.

## Test shared folder

Example: share from@domain.ltd's `Sent` folder to user `testing@domain.ltd`.

> WARNING: Do not forget the dot before IMAP command.

```
# telnet localhost 143                # <- Type this.
* OK [...] Dovecot ready.

. login from@domain.ltd passwd        # <- Type this.
                                      # Login with full email address and password
. OK [... ACL ..] Logged in

. SETACL Sent testing@domain.ltd rli  # <- Type this.
                                      # Share folder `Sent` with user testing@domain.ltd,
                                      # with permissions: read (r), lookup (l) and insert (i).
. OK Setacl complete.

^]                                    # <- Press `Ctrl + ]` to exit telnet.
telnet> quit
```

Log into Roundcube webmail or SOGo as user `testing@domain.ltd`, you should
see the shared folder.

Some more details:

* After you shared folder with `SETACL` command, dovecot will insert a record
  in MySQL database.

    * With OpenLDAP backend, it's stored in `iredadmin.share_folder`.
    * With MySQL/MariaDB/PostgreSQL backends, it's stored in `vmail.share_folder`.

```
# mysql -uroot -p
mysql> USE vmail;
mysql> SELECT * FROM share_folder;
+-----------------+--------------------+-------+
| from_user       | to_user            | dummy |
+-----------------+--------------------+-------+
| from@domain.ltd | testing@domain.ltd | 1     |
+-----------------+--------------------+-------+
```

## References

* Dovecot wiki:

    * [Mailbox sharing between users (v2.0+)](http://wiki2.dovecot.org/SharedMailboxes/Shared)
    * [Mailbox sharing between users (v1.2+)](http://wiki.dovecot.org/SharedMailboxes/Shared)

* Roundcubemail has official plugin `acl` to manage mailbox sharing.
* SOGo groupware supports mailbox sharing by default: right-click IMAP folder, choose `Sharing`.
* [Imap-ACL-Extension for Thunderbird](https://addons.mozilla.org/en-US/thunderbird/addon/imap-acl-extension/), manage acls/permissions for shared mailboxes/folders on imap servers.