Source: https://help.spamfoo.com/guides/system-requirements Last updated: 2026-10-27 *** # System Requirements Check that your server can run SpamFoo Client before you install it. This page lists the hardware, operating systems, and network access SpamFoo Client needs. > **Using SmarterMail?** SmarterMail downloads and runs SpamFoo Client for you, but the server still needs the hardware and network access on this page. ## Hardware | Resource | Minimum | Recommended | | --- | --- | --- | | Processor | 2 cores, x64 | 4 or more cores, x64 | | Memory | 1 GB free | 2 GB free | | Disk space | 2 GB free | 5 GB free | | Graphics card (GPU) | (Optional) SpamFoo Client runs on the processor by default. Servers with an NVIDIA GPU can [turn on GPU acceleration](https://help.spamfoo.com/guides/gpu-acceleration). | | > **Processor** SpamFoo Client requires an x64 (AMD64) processor. ARM processors are not supported. ### Disk Space Disk use grows over time. These things take up the most space: - **Scan history:** one record per message, kept for the Retention Period (7 days by default). Daily totals are kept for 90 days. - **Stored messages:** the subject and body of scanned messages, up to the Maximum Stored Messages limit. - **Nightly backups:** copies of the databases, 7 nights by default, on the same disk. - **Log files:** deleted after the Retention Period. Detailed logging and debug codes write much more. - **GPU acceleration:** when turned on, SpamFoo Client downloads a larger build of itself that includes NVIDIA's libraries. The **Storage** card on **System > Status** shows the database size and where each folder is. To use less space, change these on **System > Settings**: - Lower [Retention Period](https://help.spamfoo.com/api/settings#retention-period) in the **Scan History** card. - Lower [Maximum Stored Messages](https://help.spamfoo.com/api/settings#maximum-stored-messages), or turn off [Store Message Content](https://help.spamfoo.com/api/settings#store-message-content), in the **Message Content** card. Without stored content, you can't read messages on the **Messages** page. - Lower [Backups to Keep](https://help.spamfoo.com/api/settings#backups-to-keep) in the **Database Backups** card. - In the **Logging** card, set [Log Level](https://help.spamfoo.com/guides/monitoring#log-level) to **Normal** and clear **Debug Log Codes**. The database file shrinks only when SpamFoo Client compacts it, which happens each time it starts and once a week. Restart it to free the space right away. ## Supported Operating Systems | Platform | Supported Versions | | --- | --- | | Windows Server | 2016, 2019, 2022, 2025 | | Windows | 10, 11 | | Ubuntu | 22.04 and later LTS versions | | Debian | 12 and later | | Red Hat Enterprise Linux | 8 and later | | CentOS Stream | 9 and later | | AlmaLinux | 8.10 and later | | Rocky Linux | 8.10 and later | | Fedora | 43 and later | | Docker | Linux x64 hosts (see [Docker](https://help.spamfoo.com/guides/system-requirements#docker)) | Only versions that still get updates from their maker are supported. ## Software Prerequisites SpamFoo Client includes most of what it needs to run, including the .NET runtime. - **Windows:** Nothing else is needed. - **Linux archive:** The server needs the ICU library (`libicu`), which SpamFoo Client uses to read dates and text in different languages. Many servers already have it. On Red Hat, CentOS Stream, AlmaLinux, Rocky Linux, and Fedora, run `sudo dnf install libicu`. On Ubuntu and Debian, run `sudo apt install libicu-dev`. - **Docker:** The image already includes everything. - **GPU acceleration:** Also needs the NVIDIA driver. ## Network Requirements ### Ports SpamFoo Client listens on **port 16253** (HTTP). Your mail server sends messages to this port for scanning, and you open the admin console on it. In standalone mode you can choose another port with [`SPAMFOO_PORT`](https://help.spamfoo.com/guides/configure#port). Who can connect depends on how you run SpamFoo Client: - **Installed on the server:** Only programs on the same server can connect. If your mail server runs on another computer, set the `SPAMFOO_BIND_ADDRESS` environment variable. See [Configure SpamFoo Client](https://help.spamfoo.com/guides/configure#env-network). - **Docker:** Other computers and containers can connect once you publish the port, such as with `-p 16253:16253`. The Docker example in [Install SpamFoo Client](https://help.spamfoo.com/guides/install#docker) publishes it only on the host's `127.0.0.1` address. > **Warning** Do not open port 16253 to the internet. Allow only your mail servers to reach it. ### Outbound Access SpamFoo Client needs outbound HTTPS (port 443) access to these addresses: | Address | Used For | | --- | --- | | `global-api.spamfoo.com` | Update checks, reputation data, and corrections | | `downloads.spamfoo.com` | Model, program, and phishing data downloads | | `developer.download.nvidia.com` | NVIDIA libraries, only when GPU acceleration is turned on | All message scanning happens on your server. - The first start needs this access to check the license and download the models. - After that, if SpamFoo Client loses access, it keeps scanning mail with the models it already has. - While access is down, models, phishing data, and reputation data are not updated. ## Docker SpamFoo Client is also available as a Docker image, `spamfoo/spamfoo-client`. The image includes everything SpamFoo Client needs, including the admin console and the `spamfoo-client` commands. Models download the first time it starts with a license key. | Requirement | Details | | --- | --- | | Host | Linux on x64 | | Port | 16253 | | Storage | A volume mounted at `/data`, so settings, models, and history survive when the container is replaced | GPU acceleration is not available in the Docker image. ## Mail Server Compatibility | Mail Server | How It Connects | Details | | --- | --- | --- | | SmarterMail | Built in | [Set Up SmarterMail](https://help.spamfoo.com/integrations/smartermail/setup) | | Other mail servers | Local HTTP API | [How Integration Works](https://help.spamfoo.com/integrations) | ## Next Steps When your server meets these requirements, go to [Install SpamFoo Client](https://help.spamfoo.com/guides/install).