!!! warning "Implementation of Rspamd into DMS is WIP!"
## About
Rspamd is a "fast, free and open-source spam filtering system". It offers high performance as it is written in C. Visit [their homepage][homepage] for more details.
## Integration & Configuration
We provide a very simple but easy to maintain setup of RSpamd. The proxy worker operates in [self-scan mode][proxy-self-scan-mode]. This simplifies the setup as we do not require a normal worker. You can easily change this though by [overriding the configuration by DMS](#providing-overriding-settings).
### Providing & Overriding Settings
DMS brings sane default settings for Rspamd. They are located at `/etc/rspamd/local.d/` inside the container (or `target/rspamd/local.d/` in the repository). If you want to change these settings and / or provide your own settings, you can
1. place files at `/etc/rspamd/override.d/` which will override Rspamd settings and DMS settings
2. (re-)place files at `/etc/rspamd/local.d/` to override DMS settings and merge them with Rspamd settings
You can find a list of all Rspamd modules [on their website][modules].
When using Rspamd, the [RBL module](https://rspamd.com/doc/modules/rbl.html) is enabled by default. As a consequence, Rspamd will do a variety of DNS requests. Amongst other things, Rspamd will query DNS block lists (DNSBLs).
There are a variety of issues involved when using DNSBLs. Rspamd will try to mitigate some of them by properly evaluating all return codes. We urge you not to rely on this though.
If you want to use RBLs, **try to use your own DNS resolver** and make sure it is set up correctly, i.e. it should be a non-public &**recursive** resolver. Otherwise, you might not be able ([see this Spamhaus post](https://www.spamhaus.org/faq/section/DNSBL%20Usage#365)) to make use of the block lists.
DMS disables certain modules (clickhouse, elastic, greylist, neural, reputation, spamassassin, url_redirector, metric_exporter) by default. We believe these are not required in a standard setup, and needlessly use resources. You can re-activate them by replacing `/etc/rspamd/local.d/<MODULE>.conf` or overriding DMS' default with `/etc/rspamd/override.d/<MODULE>.conf`.
DMS does not set a default password for the controller worker. You may want to do that yourself. In setup where you already have an authentication provider in front of the Rspamd webpage, you may add `secure_ip = "0.0.0.0/0";` to `worker-controller.inc` to disable password authentication inside Rspamd completely.
We currently lack easy integration for DKIM signing outgoing mails. We use OpenDKIM though which works just as well. If you want to use Rspamd for DKIM signing, you need to provide all settings yourself and probably also set the environment `ENABLE_OPENDKIM=0`. Rspamd will still check for valid DKIM signatures for incoming mail by default.
