mailcow-dockerized-docs/docs/manual-guides/Rspamd/u_e-rspamd.en.md

Rspamd is used for AV handling, DKIM signing and SPAM handling. It's a powerful and fast filter system. For a more in-depth documentation on Rspamd please visit its [own documentation](https://rspamd.com/doc/index.html).

## Learn Spam & Ham

Rspamd learns mail as spam or ham when you move a message in or out of the junk folder to any mailbox besides trash.
This is achieved by using the Sieve plugin "sieve_imapsieve" and parser scripts.

Rspamd also auto-learns mail when a high or low score is detected (see https://rspamd.com/doc/configuration/statistic.html#autolearning). We configured the plugin to keep a sane ratio between spam and ham learns.

The bayes statistics are written to Redis as keys `BAYES_HAM` and `BAYES_SPAM`.

Besides bayes, a local fuzzy storage is used to learn recurring patterns in text or images that indicate ham or spam.

You can also use Rspamd's web UI to learn ham and / or spam or to adjust certain settings of Rspamd.

### Learn Spam or Ham from existing directory

You can use a one-liner to learn mail in plain-text (uncompressed) format:
=== "docker compose (Plugin)"

    ``` bash
    # Ham
    for file in /my/folder/cur/*; do docker exec -i $(docker compose ps -q rspamd-mailcow) rspamc learn_ham < $file; done
    # Spam
    for file in /my/folder/.Junk/cur/*; do docker exec -i $(docker compose ps -q rspamd-mailcow) rspamc learn_spam < $file; done
    ```

=== "docker-compose (Standalone)"

    ``` bash
    # Ham
    for file in /my/folder/cur/*; do docker exec -i $(docker-compose ps -q rspamd-mailcow) rspamc learn_ham < $file; done
    # Spam
    for file in /my/folder/.Junk/cur/*; do docker exec -i $(docker-compose ps -q rspamd-mailcow) rspamc learn_spam < $file; done
    ```

Consider attaching a local folder as new volume to `rspamd-mailcow` in `docker-compose.yml` and learn given files inside the container. This can be used as workaround to parse compressed data with zcat. Example:

```bash
for file in /data/old_mail/.Junk/cur/*; do rspamc learn_spam < zcat $file; done
```

### Reset learned data (Bayes, Neural)

You need to delete keys in Redis to reset learned data, so create a copy of your Redis database now:

**Backup database**

```bash
# It is better to stop Redis before you copy the file.
cp /var/lib/docker/volumes/mailcowdockerized_redis-vol-1/_data/dump.rdb /root/
```

**Reset Bayes data**
=== "docker compose (Plugin)"

    ``` bash
    docker compose exec redis-mailcow sh -c 'redis-cli --scan --pattern BAYES_* | xargs redis-cli del'
    docker compose exec redis-mailcow sh -c 'redis-cli --scan --pattern RS* | xargs redis-cli del'
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose exec redis-mailcow sh -c 'redis-cli --scan --pattern BAYES_* | xargs redis-cli del'
    docker-compose exec redis-mailcow sh -c 'redis-cli --scan --pattern RS* | xargs redis-cli del'
    ```

**Reset Neural data**
=== "docker compose (Plugin)"

    ``` bash
    docker compose exec redis-mailcow sh -c 'redis-cli --scan --pattern rn_* | xargs redis-cli del'
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose exec redis-mailcow sh -c 'redis-cli --scan --pattern rn_* | xargs redis-cli del'
    ```

**Reset Fuzzy data**
=== "docker compose (Plugin)"

    ``` bash
    # We need to enter the redis-cli first:
    docker compose exec redis-mailcow redis-cli
    # In redis-cli:
    127.0.0.1:6379> EVAL "for i, name in ipairs(redis.call('KEYS', ARGV[1])) do redis.call('DEL', name); end" 0 fuzzy*
    ```

=== "docker-compose (Standalone)"

    ``` bash
    # We need to enter the redis-cli first:
    docker-compose exec redis-mailcow redis-cli
    # In redis-cli:
    127.0.0.1:6379> EVAL "for i, name in ipairs(redis.call('KEYS', ARGV[1])) do redis.call('DEL', name); end" 0 fuzzy*
    ```

**Info**

If redis-cli complains about...

```text
(error) ERR wrong number of arguments for 'del' command
```

...the key pattern was not found and thus no data is available to delete - it is fine.


## CLI tools
=== "docker compose (Plugin)"

    ``` bash
    docker compose exec rspamd-mailcow rspamc --help
    docker compose exec rspamd-mailcow rspamadm --help
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose exec rspamd-mailcow rspamc --help
    docker-compose exec rspamd-mailcow rspamadm --help
    ```

## Disable Greylisting

Only messages with a higher score will be considered to be greylisted (soft rejected). It is bad practice to disable greylisting.

You can disable greylisting server-wide by editing:

`{mailcow-dir}/data/conf/rspamd/local.d/greylist.conf`

Add the line:

```cpp
enabled = false;
```

Save the file and restart "rspamd-mailcow":
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

## Spam filter thresholds (global)

Each user is able to change [their spam rating individually](../mailcow-UI/u_e-mailcow_ui-spamfilter.en.md). To define a new **server-wide** limit, edit `data/conf/rspamd/local.d/actions.conf`:

```cpp
reject = 15;
add_header = 8;
greylist = 7;
```

Save the file and restart "rspamd-mailcow":
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

Existing settings of users will not be overwritten!

To reset custom defined thresholds, run:
=== "docker compose (Plugin)"

    ``` bash
    source mailcow.conf
    docker compose exec mysql-mailcow mysql -umailcow -p$DBPASS mailcow -e "delete from filterconf where option = 'highspamlevel' or option = 'lowspamlevel';"
    # or:
    docker compose exec mysql-mailcow mysql -umailcow -p$DBPASS mailcow -e "delete from filterconf where option = 'highspamlevel' or option = 'lowspamlevel' and object = 'only-this-mailbox@example.org';"
    ```

=== "docker-compose (Standalone)"

    ``` bash
    source mailcow.conf
    docker-compose exec mysql-mailcow mysql -umailcow -p$DBPASS mailcow -e "delete from filterconf where option = 'highspamlevel' or option = 'lowspamlevel';"
    # or:
    docker-compose exec mysql-mailcow mysql -umailcow -p$DBPASS mailcow -e "delete from filterconf where option = 'highspamlevel' or option = 'lowspamlevel' and object = 'only-this-mailbox@example.org';"
    ```
```
source mailcow.conf
docker compose exec mysql-mailcow mysql -umailcow -p$DBPASS mailcow -e "delete from filterconf where option = 'highspamlevel' or option = 'lowspamlevel';"
# or:
# docker compose exec mysql-mailcow mysql -umailcow -p$DBPASS mailcow -e "delete from filterconf where option = 'highspamlevel' or option = 'lowspamlevel' and object = 'only-this-mailbox@example.org';"
```

## Custom reject messages

The default spam reject message can be changed by adding a new file `data/conf/rspamd/override.d/worker-proxy.custom.inc` with the following content:

```
reject_message = "My custom reject message";
```

Save the file and restart Rspamd:
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

While the above works for rejected mails with a high spam score, prefilter reject actions will ignore this setting. For these maps, the multimap module in Rspamd needs to be adjusted:

1. Find prefilet reject symbol for which you want change message, to do it run: `grep -R "SYMBOL_YOU_WANT_TO_ADJUST" /opt/mailcow-dockerized/data/conf/rspamd/`

2. Add your custom message as new line:

```
GLOBAL_RCPT_BL {
  type = "rcpt";
  map = "${LOCAL_CONFDIR}/custom/global_rcpt_blacklist.map";
  regexp = true;
  prefilter = true;
  action = "reject";
  message = "Sending mail to this recipient is prohibited by postmaster@your.domain";
}
```

3. Save the file and restart Rspamd:
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

## Discard instead of reject

If you want to silently drop a message, create or edit the file `data/conf/rspamd/override.d/worker-proxy.custom.inc` and add the following content:

```
discard_on_reject = true;
```

Restart Rspamd:
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

## Wipe all ratelimit keys

If you don't want to use the UI and instead wipe all keys in the Redis database, you can use redis-cli for that task:
=== "docker compose (Plugin)"

    ``` bash
    docker compose exec redis-mailcow sh
    # Unlink (available in Redis >=4.) will delete in the backgronud
    redis-cli --scan --pattern RL* | xargs redis-cli unlink
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose exec redis-mailcow sh
    # Unlink (available in Redis >=4.) will delete in the backgronud
    redis-cli --scan --pattern RL* | xargs redis-cli unlink
    ```

Restart Rspamd:
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

## Trigger a resend of quarantine notifications

Should be used for debugging only!
=== "docker compose (Plugin)"

    ``` bash
    docker compose exec dovecot-mailcow bash
    mysql -umailcow -p$DBPASS mailcow -e "update quarantine set notified = 0;"
    redis-cli -h redis DEL Q_LAST_NOTIFIED
    quarantine_notify.py
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose exec dovecot-mailcow bash
    mysql -umailcow -p$DBPASS mailcow -e "update quarantine set notified = 0;"
    redis-cli -h redis DEL Q_LAST_NOTIFIED
    quarantine_notify.py
    ```

## Increase history retention

By default Rspamd keeps 1000 elements in the history.

The history is stored compressed.

It is recommended not to use a disproportionate high value here, try something along 5000 or 10000 and see how your server handles it:

Edit `data/conf/rspamd/local.d/history_redis.conf`:

```
nrows = 1000; # change this value
```

Restart Rspamd afterwards:
=== "docker compose (Plugin)"

    ``` bash
    docker compose restart rspamd-mailcow
    ```

=== "docker-compose (Standalone)"

    ``` bash
    docker-compose restart rspamd-mailcow
    ```

## Adding Rspamd modules

Download the module and save it in the following path: `data/conf/rspamd/plugins.d/`.

Next, add any necessary configuration for your module to `data/conf/rspamd/rspamd.conf.local`. \
If you have a module named `my_plugin.lua`, configuration might look like the following:

```
# rspamd.conf.local  
my_plugin {
    some_setting = "some value";
}
```

If your module does not require any additional configuration, simply add an empty configuration block, for example:

```
# rspamd.conf.local  
my_plugin { }
```

If you do not add a configuration block, the module will be automatically disabled, and the rspamd-mailcow container log will contain a message such as:

```
mailcowdockerized-rspamd-mailcow-1  | 2023-05-20 14:01:32 #1(main) <sh6j9z>; cfg; rspamd_config_is_module_enabled: lua module my_plugin is enabled but has not been configured
mailcowdockerized-rspamd-mailcow-1  | 2023-05-20 14:01:32 #1(main) <sh6j9z>; cfg; rspamd_config_is_module_enabled: my_plugin disabling unconfigured lua module
```

If you have successfully configured your module, the rspamd-mailcow container logs should show:

```
mailcowdockerized-rspamd-mailcow-1  | 2023-05-20 14:04:50 #1(main) <8ayxpf>; cfg; rspamd_init_lua_filters: init lua module my_plugin from /etc/rspamd/plugins.d//my_plugin.lua; digest: 5cb88961e5
```