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Roundcube App


Roundcube webmail is a browser-based multilingual IMAP client with an application-like user interface.

Default Setup

Roundcube is pre-configured for use with Cloudron Email.

Multi-domain Setup

Users can login with their email and password to access their mailbox. If the Cloudron has two domains, and, the user can login using and Aliases can be added as identities under Roundcube settings.

External domains

The roundcube app does not support adding domains that are not managed in Cloudron. Consider using Snappymail app (Rainloop fork) as an alternative.

Custom config

Custom config can be placed in /app/data/customconfig.php using the File Manager.

Vacation Email

An out of office / vacation mail message can be setup using Sieve filters.

A vacation message can be set in Settings -> Filters -> Add filter -> Vacation message action.

Forwarding all emails

To forward all emails to an external mail, setup a Sieve filter in Settings -> Filters -> Add a filter -> Forward to


Plugins can be installed from plugin release tarballs. Please check plugin compatibility with your Roundcube version as several of the listed plugins are out-of-date and may break Roundcube.

  • Upload the release tarball of the plugin using the File Manager into /app/data/plugins and extract it. After extract, you might need to prettify the directory name. For example, rename roundcube-contextmenu-3.3 to just contextmenu. Make a note of this directory name since it required below.

  • Change the ownership of the extracted plugin to www-data using the File Manager.

  • Add the plugin to $config['plugins'] in /app/data/customconfig.php. The name below must match the name of the directory in the first step.

    array_push($config['plugins'], 'myplugin');
  • Some plugin release tarballs do not contain dependancies and have to be installed via composer. composer requires a lot of RAM for it's resolution mechanism. For this reason, first bump the memory limit of the app to 2GB (you can reset back the memory limit after plugin installation). Open a Web Terminal and run the following:
    # cd /app/data/plugins/<plugin>
    # composer install --no-dev
    # chown -R www-data:www-data .

Cannot edit root composer.json

The official plugin repository suggests installing plugins by editing the local /app/code/composer.json. This method of installation is not supported since code on Cloudron is read only.

Enabling PGP support

The Enigma plugin can be used to enable PGP support. The Enigma plugin is part of the roundcube code and no installation is required. To enable the plugin:

  • Add the following lines to /app/data/customconfig.php:
    array_push($config['plugins'], 'enigma');
    $config['enigma_pgp_homedir'] = '/app/data/enigma';
  • Create the directory where enigma will save the PGP keys on the server:
    mkdir /app/data/enigma
    chown www-data:www-data /app/data/enigma
  • New PGP keys can be created or existing ones can be imported in Settings -> PGP Keys

  • When composing new mail, you will see an Encryption icon in the tool bar.

Changing the title

Add the following lines to /app/data/customconfig.php using the File Manager:

    $config['product_name'] = 'My Hosting Company';


Skins can be installed as follows:

  • Extract the skin using the File Manager into /app/data/skins.

  • Change the ownership of the extracted skin to www-data.

  • Set the new skin as the default skin by adding this line in /app/data/customconfig.php:

    $config['skin'] = 'newskin_directory_name';

To customize CSS and logo, it's best to create a copy of an existing skin and make changes as needed.

# cd /app/data/skins
# cp -Lr larry customskin
... make changes in customskin ...
# chown -R www-data:www-data customskin
  • Set the new skin as the default skin by adding this line in /app/data/customconfig.php:
    $config['skin'] = 'customskin';

By default, the search field only searches the current folder. To search across all folders, change the Scope.

Upload size

  • To increase the upload size, edit /app/data/customconfig.php. Note that Roundcube only uses 1/3rd of the size below for the attachment.
    $config['max_message_size'] = '100M';
  • Edit /app/data/php.ini accordingly:
    post_max_size = 75M
    upload_max_filesize = 75M

Be sure to restart the app after making the above changes.