The main repository is at fho/rspamd-iscan. This repo provides the Docker image and Helm chart.

rspamd-iscan is a daemon that monitors IMAP mailboxes and sends new mails to Rspamd for spam analysis and training. It decouples spam filtering from mail delivery — allowing the MDA, Rspamd, and rspamd-iscan to run on entirely separate hosts. For example, you can filter mails on the IMAP server of your third-party provider using your self-hosted Rspamd instance. It is similar to isbg but uses Rspamd instead of SpamAssassin.

Build and run locally:

docker build -t rspamd-iscan .

docker run -d \
  --name rspamd-iscan \
  -v /path/to/config.toml:/etc/rspamd-iscan/config.toml \
  rspamd-iscan

Or pull the pre-built image:

docker pull guestros/rspamd-iscan

The Helm chart deploys the full stack: Rspamd + rspamd-iscan, with an optional in-cluster Redis.

Copy helm/examplevalues.yaml, fill in your IMAP details and password, then install:

cp helm/examplevalues.yaml myvalues.yaml
# edit myvalues.yaml

helm install rspamd-iscan oci://ghcr.io/justinguese/rspamd-iscan \
  -f myvalues.yaml -n spamfilter --create-namespace

No manual secret creation needed — all credentials go in your values file and are stored in a Kubernetes Secret by Helm. The Rspamd controller password is auto-generated on first install.

All options are documented in helm/rspamd-iscan/values.yaml.

The rspamdIscan.mailboxes section controls which IMAP folders are used:

Note: Undetected, Unscanned, and BackupMailbox are non-standard folders — most providers won't create them automatically. Create them manually in your mail client or provider's webmail before deploying.

Recommended mail provider setup: Configure a server-side rule to deliver all incoming mail into the scan folder instead of INBOX. rspamd-iscan will then sort it automatically.

I am using Hostinger Email (~€1/month) — good, cheap, and works great with this setup. If this saved you some time, feel free to use the referral link and buy me a coffee ☕

• Missed spam in inbox → drag it to undetected — rspamd-iscan will use it as a spam training example
• Legitimate mail in spam → drag it to ham — rspamd-iscan will use it as a ham training example

The GitHub Actions workflow builds and publishes a new Docker image automatically:

• On every push to main (e.g. Dockerfile changes)
• Weekly, if the upstream repo (fho/rspamd-iscan) has new commits — checked via commit SHA caching, so no unnecessary rebuilds

To publish images from your own fork, configure:

1. Settings → Secrets and variables → Actions
2. Add variable DOCKERHUB_USERNAME — your Docker Hub username
3. Add secret DOCKERHUB_TOKEN — a Docker Hub access token