A security checkpoint in front of your mailboxes.
Most email threats are stopped, or not, before a message ever reaches a mailbox. Built-in filtering helps, but a dedicated email security gateway gives you a controllable checkpoint where spam, viruses, phishing and malware are intercepted before they touch your mail server or your users. Proxmox Email Gateway is the open source platform for exactly that: a full-featured anti-spam and anti-virus gateway that sits in front of any mail system. Node deploys and manages it on UK infrastructure, tuning the rules, managing the quarantine and watching the threat picture so your inboxes stay clean and your domain reputation stays intact.
What Proxmox Email Gateway is
Proxmox Email Gateway is an open source email security platform that filters mail between the internet and your mail server. It is not a mail server itself; it is the protective layer in front of one. All mail for your domains is routed through the gateway, where it is inspected, scored and filtered before clean messages are passed on to your actual mail platform.
Because it sits in front of the mail server rather than inside it, it works with any backend: a self-hosted Mailcow platform, Microsoft 365, Google Workspace or any standard SMTP server. You keep your existing mailboxes and add a dedicated, independently managed security layer in front of them.
It filters in both directions. Inbound mail is screened for spam, viruses and phishing before delivery. Outbound mail is screened too, so a compromised account or a malware infection cannot quietly turn your domain into a source of spam and wreck your sending reputation.
What it protects against
A modern email gateway has to do more than catch obvious spam. Proxmox Email Gateway combines several techniques into layered defence.
Spam filtering - statistical and rule-based scoring, sender reputation checks, greylisting and blocklist integration combine to catch unwanted mail with a low false-positive rate.
Virus and malware scanning - attachments and message content are scanned for viruses and malware before delivery, with policies for handling dangerous file types.
Phishing and spoofing defence - SPF, DKIM and DMARC checks on inbound mail catch spoofed senders and impersonation attempts, a primary vector for business email compromise.
Outbound protection - filtering of outbound mail catches compromised accounts before they damage your domain reputation and your ability to deliver legitimate email.
Control, visibility and quarantine
Filtering is only useful if it is manageable and transparent. The gateway gives administrators and users the right level of control over what is blocked and why.
Central policy - filtering rules, allow and block lists and per-domain policy are managed in one place across all your domains, independent of the mailboxes themselves.
Quarantine - suspected spam and dangerous mail is held in quarantine rather than silently deleted. Users can receive a regular quarantine digest and release legitimate mail themselves, reducing the burden on administrators.
Reporting and tracking - detailed statistics and full message tracking show what is being filtered and let an administrator trace exactly what happened to any given message, which is invaluable when a sender asks why their mail did not arrive.
Tuning - we tune the scoring and rules to your organisation's tolerance, balancing aggressive threat blocking against the risk of catching legitimate mail.
How Proxmox Email Gateway fits with the rest of your platform
The gateway is the security layer in front of whatever mail platform you run. It pairs naturally with a managed Mailcow email server to give you a complete, self-hosted email stack with dedicated security in front of it, but it protects commercial mail platforms just as well. It complements our wider security practice, sitting alongside the hosted managed WAF that protects your web applications and the systems hardening we apply across your infrastructure. We monitor the gateway through our Zabbix and Grafana observability stack so mail flow, queue health and threat volumes are watched continuously.
Defence in depth for the channel attackers use most - email remains the primary entry point for phishing, ransomware and business email compromise. Relying solely on the filtering built into your mailboxes puts all your defence in one layer, inside the system the attacker is trying to reach. A dedicated, independently managed email gateway intercepts threats before they get that far, protects your outbound reputation, and gives you central control and full visibility over what reaches your people. Node runs it as a managed service so the rules stay tuned and the threats stay outside.
Talk to us about email security.
Drop us a line and our team will discuss your email threat exposure and how a managed Proxmox Email Gateway can protect your inboxes and your domain reputation.
Frequently asked questions
What is Proxmox Email Gateway?
Proxmox Email Gateway is an open source email security and anti-spam gateway. It sits in front of your mail server and filters inbound and outbound email, blocking spam, viruses, phishing and other threats before they reach your users. Node Digital deploys and manages it for UK organisations as a protective layer in front of any mail platform.
Does Proxmox Email Gateway work with Microsoft 365 and Google Workspace?
Yes. Proxmox Email Gateway is mail-server agnostic. It can filter mail for Microsoft 365, Google Workspace, a self-hosted Mailcow server or any standard SMTP platform by routing your domain's mail through the gateway first. You keep your existing mailboxes and add a dedicated security layer in front of them.
How is this different from the spam filtering built into my mail server?
A dedicated gateway filters threats before they ever reach your mail server, reducing load and adding defence in depth. It provides centralised policy, quarantine, detailed reporting and outbound filtering across all your domains, with rules and tuning managed independently of the mailboxes themselves.
Can it filter outbound email as well as inbound?
Yes. Proxmox Email Gateway filters outbound mail too, which helps protect your domain reputation by catching compromised accounts or malware sending through your systems before that traffic damages your ability to deliver legitimate mail.
Who hosts and supports Proxmox Email Gateway in the UK?
Node Digital runs Proxmox Email Gateway as a production-grade managed service on UK infrastructure or in your own cloud, handling deployment, rule tuning, quarantine management, upgrades, monitoring and integration with your existing mail platform.