Enterprise-grade email filtering that runs entirely within British borders. Built on a clustered Proxmox Mail Gateway, our Cloud Antispam service delivers rock-solid inbound and outbound protection — without routing your sensitive communications through US hyperscalers or third-party SaaS vendors.
Dual-node Proxmox Mail Gateway cluster eliminates single points of failure. If one node drops, mail routing continues seamlessly — zero downtime, zero missed messages.
Your mail metadata, sender reputation data, and quarantine logs never leave UK soil. Full UK GDPR compliance by design, not by configuration.
We size, deploy, and manage the entire gateway stack. No per-seat SaaS subscriptions. One transparent quote covers everything for your domain count and mail volume.
Optimized hardware, fast deployment, and UK-based support to keep your platform stable and predictable.
We can customize CPU, RAM, storage, and networking to match your workload.
Why It Matters
The moment your email passes through a US-based filtering service — Microsoft 365 Defender, Proofpoint, Mimecast — it becomes subject to US jurisdiction, CLOUD Act surveillance requests, and opaque data-sharing practices that you cannot audit. For law firms, accountancies, healthcare providers, and any business handling confidential correspondence, this is an unacceptable risk. Our Cloud Antispam gateway keeps every byte of your mail metadata on British soil, under British law, with a team you can call.
Most businesses don't realise what they're signing up for.
US law allows federal agencies to compel American companies to hand over data stored anywhere in the world — including your filtered email logs and sender metadata.
SaaS antispam vendors own your spam policies, your quarantine history, and your allowlists. Switch providers and you start from zero — at a price they set.
Subscription costs scale with every new employee. Add 20 staff and your monthly bill jumps overnight. Our model quotes on domain volume and mail flow — not headcount.
You rarely know why a legitimate email landed in quarantine. Proprietary ML models offer no transparency, no tuneable rules, and no local override capability.
If your SaaS vendor has an outage — and all of them do — your mail queue stalls. Clustered on-premise gateways continue routing regardless of upstream provider issues.
Post-Brexit adequacy decisions are not permanent. Processing personal data through a US intermediary introduces compliance risk that a UK-sovereign stack eliminates by design.
A direct comparison on what actually matters for enterprise email security.
| Feature | UKNode Cloud Antispam | Microsoft 365 / EOP | Typical SaaS Antispam |
|---|---|---|---|
| Data Residency | 🇬🇧 UK Only | 🌍 Global (US jurisd.) | 🌍 Varies |
| US CLOUD Act Risk | ✅ None | ❌ Exposed | ❌ Exposed |
| Pricing Model | Fixed quote (domain-based) | Per-seat / per-month | Per-seat / per-month |
| High Availability | Active/Active cluster | Microsoft SLA only | Vendor dependent |
| Filtering Transparency | Full rule access + logs | Black box | Black box |
| Custom Policies | Fully customisable | Limited | Limited |
| Inbound Filtering | ✅ Included | ✅ Included | ✅ Included |
| Outbound Relay & Filtering | ✅ Included | ⚠️ Add-on | ⚠️ Add-on |
| DKIM / SPF / DMARC | ✅ Enforced | ✅ Included | ✅ Included |
| Quarantine Web UI (per domain) | ✅ Per-domain interface | ⚠️ Admin-centric | ⚠️ Varies |
| UK Support Team | ✅ Direct line | ❌ Ticket only | ❌ Ticket only |
| Vendor Lock-In | None — your config, your logs | High | High |
A single MX record change routes your mail through an Active/Active cluster. Every message passes through multiple filtering layers before reaching your server.
If Node 1 becomes unavailable, Node 2 continues to receive and process mail without interruption. No DNS failover delay.
Proxmox Mail Gateway is an open-source, enterprise-grade email security platform that gives us — and you — complete visibility into every filtering decision. Unlike proprietary SaaS black boxes, every rule, every score threshold, and every quarantine action is inspectable and adjustable. Our engineers configure the cluster to your exact domain requirements, then maintain it continuously so you never have to think about false positives, rule drift, or upstream policy changes.
Most businesses focus on inbound spam. But outbound relay is equally critical. A compromised mailbox or misconfigured mail server sending spam destroys your domain reputation within hours, landing all your legitimate mail in recipients' junk folders. Our gateway sits in line on outbound too — enforcing DKIM signing, DMARC alignment, and rate limits that protect your sending reputation around the clock.
If you operate under FCA, ICO, or NHS data frameworks, your email security posture is a compliance matter — not just an IT preference. Phishing is the entry point for the majority of data breaches. A properly deployed, UK-resident mail gateway with comprehensive logging and audit trails provides the documented evidence of due diligence that regulators expect.
We don't believe enterprise email security should be priced per-seat — a model that actively penalises growth. Our Cloud Antispam service is quoted based on domain count and approximate mail volume. Whether you're protecting a single high-traffic domain or a portfolio of client domains, we'll scope a deployment that fits. Contact our team for a no-obligation discussion and written quote.
Discuss your specific architectural requirements for Cloud Antispam Gateway with our UK-based engineering team.