Learn about sieve syntax and how recipes are set up. This article is not a comprehensive list of everything that sieve can do, but rather a guide to helping you get started with sieve. If you want more information about what sieve is, see our article What is Sieve Filtering?

sing the guide to build plugins for Roundcube, I set up a "no_forward_for_groupes" plugin, in the [roundcubeRoot]/plugin/no_forward_for_groupes folder. I activated it in the [roundcubeRoot]/config/config.inc.php file by wrtiting

$config['plugins'] = array('no_forward_for_groupes');

as any other plugin.

After a bit of reading and research in the [roundcubeRoot]/program/js/app.js file (the core JS of Roundcube), I found the object I need to act with and the events to listen. The final code is just after. As you can see, I disabled a lot of other commands, as well as drag and drop. So basically I have a read-only folder, which you can't get any mails out of. I know it's kind of a specific use-case, but I hope it'll help some folks out there someday!