Build the SOGo Connector plugin

Install GNU Make, tar, and ZIP if you don't already have them installed. On Debian/Ubuntu, this can be done using

apt-get install make tar zip

Next, go to data/web inside mailcow-dockerized. Place the file thunderbird-plugins.php into that directory. Create a new directory thunderbird-plugins and place the script build-plugins.sh into it. Finally, execute the script with your hostname as an argument and piping it the names of all domains that mailcow handles. All of this can be done using the following commands:

cd data/web
curl -LO https://github.com/mailcow/mailcow-dockerized-docs/raw/master/docs/download/thunderbird-plugins.php
mkdir thunderbird-plugins
cd thunderbird-plugins
curl -Lo build-plugins.sh https://github.com/mailcow/mailcow-dockerized-docs/raw/master/docs/download/build-thunderbird-plugins.sh
chmod +x build-plugins.sh
echo example.com example.org | ./build-plugins.sh mailcow.example.com

Install it in Thunderbird

After you have set up your mailcow IMAP account in Thunderbird, download the SOGo Connector plugin for your domain, e.g. https://mailcow.example.com/thunderbird-plugins/sogo-connector-68.0.1-example.com.xpi (see data/web/thunderbird-plugins), and install it into Thunderbird. All your address books and calendars will be configured automatically.