# Setting up Synapse Simple Antispam (optional, advanced) The playbook can install and configure [synapse-simple-antispam](https://github.com/t2bot/synapse-simple-antispam) for you. It lets you fight invite-spam by automatically blocking invitiations from a list of servers specified by you (blacklisting). See the project's [documentation](https://github.com/t2bot/synapse-simple-antispam/blob/master/README.md) to learn what it does and why it might be useful to you. ## Adjusting the playbook configuration Add the following configuration to your `inventory/host_vars/matrix.example.com/vars.yml` file (adapt to your needs): ```yaml matrix_synapse_ext_spam_checker_synapse_simple_antispam_enabled: true matrix_synapse_ext_spam_checker_synapse_simple_antispam_config_blocked_homeservers: - example.com - example.net ```