Setting Up MTA

As usual with open source groupware, Kopano does not come with its own mail agent but relies on popular Linux software such as Postfix. Listing 7 shows how to integrate Postfix into the groupware. For this purpose, you first create a local Unix socket (lines 2-5) and edit two configuration files (Listing 8). Then, launch the services in question (Listing 7, lines 7-9).

01 $ sudo su
02 # mkdir -p /var/spool/kopano
03 # chown kopano:kopano /var/spool/kopano
04 # chmod go= /var/spool/kopano
05 # setfacl -m u:postfix:rwx /var/spool/kopano
06 [... Listing 8 ...]
07 # service kopano-dagent start
08 # service kopano-spooler start
09 # service postfix start
10 # exit

# Edit /etc/kopano/dagent.cfg file
lmtp_listen = unix:/var/spool/kopano/dagent.sock
# File /etc/postfix/main.cf: Define transport
virtual_transport = lmtp:unix:/var/spool/kopano/dagent.sock

Usually the Kopano admin then integrates the Mail Transfer Agent (MTA) with an LDAP service, be it OpenLDAP or Active Directory. The corresponding configuration procedure is described in the Kopano documentation [9].

Groupware Client

The setup described so far already gives you a comprehensive groupware setup, but this is only the beginning, because a number of optional use cases and extensions await.

For example, as an alternative to the web client, Kopano Core provides numerous protocols by default for use with native client apps, such as CalDAV to connect a calendar (Figure 4). If you want, you can also install Z-Push [10] to offer Outlook users the range of functions they are accustomed to from Microsoft Exchange via ActiveSync.

Figure 4: The group Calendar in Kopano feels like Outlook.

Kopano WebApp can be extended with various add-ons, such as Files for group document storage or MDM for mobile device management. WhatsApp is also available as a plugin, but only for the DeskApp desktop client.

Even an archiving tool can be installed. The Archiver [11] (although it is subject to a charge) is mainly used to store old email messages to avoid slowing down the system in the long term. Companies that need a legally compliant archiving solution can tie in Benno [12] with Kopano.

Add-on configuration files are found in the appropriate subdirectory in /etc/kopano/.

Mattermost and Kopano

One exciting option for expanding the groupware suite is adding the Mattermost group chat solution, which slots into the web client as a plugin. The installation package provided by Kopano contains both Mattermost and the integration components for Kopano.

Once the repository has been integrated and the package downloaded and unpacked, the software can be installed by typing:

sudo apt install mattermost-server

Next, you need to run a configuration script to create the required tables in the Kopano database:

$ sudo mattermost-db-configure -u <Kopano_MySQL_User> -p <Kopano_MySQL_Password> -d <Mattermost_Database_Name> -n <Mattermost_User> -o <Mattermost_Password>

Finally, the client and web server need Mattermost-specific header settings (Listing 9).

### /etc/kopano/webapp/config-mattermost.php
### Set up Mattermost URL
define('PLUGIN_MATTERMOST_URL', 'https://mattermost.<Domain>');
### Headers for Content Security, sample code in the vhost files.
[...]
### Optional headers to access Mattermost from the Kopano WebApp
Header set X-Frame-Options "ALLOW-FROM https://kopano.<Domain>/webapp/"
Header edit Content-Security-Policy ^(.*)$ "$1;frame-ancestors 'self' https://kopano.<Domain>/webapp/"
Header unset X-Frame-Options
Header unset Content-Security-Policy