SpamSentinel sits in front of your existing infrastructure with N+2 gateway redundancy, sub-14ms multi-engine inspection (SpamAssassin, ClamAV, Bayesian auto-learning), and a 96-hour zero-loss spool vault — so a dead primary server is a maintenance ticket, not an outage.
NODE-A · PRIMARY
tokyo-ap1 anycast
NODE-B · SECONDARY
osaka-ap2 anycast
NODE-C · TERTIARY
singapore-ap3 anycast
済 (sumi) — "verified": each node is stamped only after passing health checks
The Failure Mode Nobody Budgets For
Most spam filtering runs as one inline appliance or one cloud endpoint. When it drops — patch failure, DDoS, regional outage, expired cert — inbound mail doesn't queue politely. It bounces, or routes around your filtering entirely and lands unscanned in your users' inbox.
That 20-minute outage is how ransomware gets in. The window where filtering is down is the window a single unscanned phishing email reaches a finance director — and if it's your upstream mail server that's down, not the filter, most solutions have nowhere to put incoming mail. It's dropped, NDR'd, or lost. Permanently.
The Solution
Every domain resolves to a minimum of three independent gateway nodes via Anycast DNS. If a node fails health checks, traffic withdraws from that route in seconds — no DNS propagation delay, no manual failover, no single node carrying 100% of your risk.
If your primary mail server is unreachable, SpamSentinel doesn't bounce the message — it holds it. The Spool Vault retains clean, scanned mail for up to 96 hours, retrying on a backoff schedule, and releases the full queue automatically once your server is reachable. Zero-loss, not best-effort.
Every message is scored through SpamAssassin's rule-based engine, scanned by ClamAV for malware and Trojans, and checked against SURBL/DNSBL reputation lists and SPF — adding under 14ms of latency. A self-tuning Bayesian filter learns from confirmed spam/ham over time, sharpening detection without manual rule-writing. Inline scoring, not a delayed batch scan, so threats are quarantined before delivery.
How This Differs From What You Already Run
Most sysadmins are running one of two things today: SpamAssassin bundled into cPanel, or a third-party cloud spam filter sitting in front of it. Here's where each one actually stands.
Comparison reflects general, publicly documented behavior for cPanel + Apache SpamAssassin and typical third-party cloud spam filters. Specific vendors and hosting providers vary — confirm against your current setup.
100%
Gateway uptime — trailing 12 months, all Anycast nodes
<14ms
Average inline inspection latency added to mail flow
96hr
Maximum Spool Vault retention during upstream outage
SpamSentinel's filtering layer is built on proven, widely-deployed scanning engines — not a proprietary black box. Inbound mail is inspected through battle-tested spam scoring and antivirus engines before it ever reaches your mail server, so the detection logic you're evaluating is auditable, not a sealed vendor algorithm you're trusting blind.
Pricing
Billed yearly
No credit card required
Anycast DNS routing means client connections fail over to the next healthy node in under a few seconds — no single node's failure stops inbound mail. N+2 means two full nodes can be lost simultaneously before service degrades.
Most cloud filters are a single inline hop with no spooling — if your mail server is down, mail bounces. SpamSentinel adds a 96-hour Spool Vault to remove that failure mode entirely, rather than leaving you exposed to a single point of failure.
Yes — MX cutover is the only DNS change required. Most migrations are a TTL-bounded cutover window, not a maintenance outage.
Full production feature access — N+2 routing, Spool Vault, and a dedicated spam panel — on your real domain, no credit card required. Inbound mail is inspected through battle-tested spam scoring and antivirus engines, so you're evaluating it under real mail load, not a sandboxed demo.
Under 14ms average for inline multi-engine inspection (SpamAssassin + ClamAV + Bayesian filter + SURBL/DNSBL checks) — the scan time added per message, not a batch-processing delay.
Deploy N+2 redundant spam filtering with zero-loss spooling in front of your existing mail server — fully operational proof-of-concept in under a day.
Start Your 14-Day Free Trial →S$8/domain/month, billed yearly · No credit card required · Enterprise volume pricing available · Cancel anytime