Roundcube is a browser-based multilingual IMAP client with an application-like user interface. It provides full functionality you expect from an email client, including MIME support, address book, folder manipulation, message searching and spell checking.
* Install the [contextmenu](https://packagist.org/packages/johndoh/contextmenu) and [automatic addressbook](https://packagist.org/packages/projectmyst/automatic_addressbook) plugins by default
* Allow to install the [CardDAV](https://packagist.org/packages/roundcube/carddav) (address book) synchronization plugin at the installation - note that if you have installed Nextcloud or Baïkal, it will automatically add the corresponding and existing address book.
You can extend - or even override - the Roundcube configuration which is coming with this package in the file `config/<ROUNDCUBE_DOMAIN>.inc.php`. Do not edit the file `config/config.inc.php` as future upgrades will overwrite it.
#### Multi-users support
* Integrate with YunoHost users and SSO - i.e logout button, YunoHost users search
#### Plugins
You can also install other plugins - which will not be removed with upgrades. To do so, you can use the official [Plugin Repository](https://plugins.roundcube.net/).
##### From the Plugin Repository
Let's say for example that we want to install the [html5_notifier](https://packagist.org/packages/kitist/html5_notifier) plugin.
1. Connect to your server as root using SSH:
```
$ ssh admin@1.2.3.4
$ sudo -i
```
2. Log in as the `roundcube` user - which owns the roundcube directory - and navigate in it:
```
# su -s /bin/bash - roundcube
$ cd /var/www/roundcube
```
3. Install the plugin you want using composer - note that you have to specify *kitist/html5_notifier* and not only *html5_notifier*:
See https://github.com/roundcube/roundcubemail/issues/9458.
Note that you should also check the plugin homepage for additional installation steps as needed.
##### Manual installation
You can also download the plugin and put it under the `plugins/` directory. In this case, do not forget to change ownerships of this folder to `roundcube`.