HCL Notes and Domino.
Still running. Still defended.
You run HCL Domino, formerly IBM Notes, and you have heard for a decade that you should migrate. Maybe you cannot, regulatory constraints, deep integrations, institutional reality. Maybe you choose not to, because Notes still does what your business needs it to do. Either way, the major email security vendors stopped paying serious attention to Domino years ago. We did not. SpamSentinel runs natively on Domino, and the same expert team supports it now that has been supporting it since 2003.
A peer-trust handoff, not a market decision
The simple version: a customer asked us to. The Maysoft team had served HCL Domino email security customers for two decades. When the time came to step back, they reached out to DuoCircle with one condition: take care of these customers, and do not damage what we built.
That is the same condition under which DuoCircle was founded in 2014, when we acquired an email-hosting customer book on the same rule. Twelve years and over 50,000 organizations later, the rule still runs the company. SpamSentinel and InboxGenius are the products that came across in that handoff, and they are still maintained because the customers running them still need them maintained.
SpamSentinel sits inside DuoCircle's broader Protect portfolio, alongside Spam Filtering, Phishing Protection, and Visual Mail Verification. SpamSentinel is the Domino-native option in that lineup. The other three are for Microsoft 365 and Exchange shops.
What is in the box
Spam filtering, anti-phishing, malware and macro scanning, preferred-sender learning, and a tunable rule engine, all running natively on Domino. One product, one install, one expert team behind the support line.
Real-time spam filtering
Inbound mail is scored and filtered as it arrives at the Domino server, not in batches and not on a relay sitting outside the mail path. Filtering happens where Domino routes mail, with the Domino administrative model the team you have already knows how to operate.
Anti-phishing at the Domino layer
Phishing and impersonation attempts get blocked before they touch a mailbox database, not after a user has already clicked. The same patterns the major vendors stopped tuning for Domino, still tuned, still updated, still shipped.
Malware and macro scanning
Attachments and message bodies scanned against current threat signatures. MacroKiller, included with SpamSentinel, focuses specifically on macro-bearing attachments, the delivery pattern still in heavy rotation against Domino shops.
InboxGenius preferred-sender learning
Learns from user actions and mailbox patterns to identify the senders each user actually wants to hear from, and routes the rest to Junk. Reduces the false-positive triage burden on the help desk without forcing users to maintain whitelists by hand.
Tunable rules for real Domino environments
Content-aware policy rules you can adjust for the false-positive cases that actually show up in your environment, not the ones a generic cloud filter assumes. Practical knobs for practical operators.
Native Domino integration
Installs directly on Domino. No relay added to the mail path, no proxy that another team has to manage, no second product to operate alongside Notes. Domino administrators run it the same way they run everything else.
The audience
- HCL Domino and IBM Notes administrators with active Domino mail infrastructure they intend to keep
- Regulated enterprises (financial, healthcare, government) with deep Notes investments and integration constraints that make a cloud migration impractical
- Organizations the major email security vendors will not engage with at the Domino platform tier
- IT teams who would rather harden the deployment they have than rip and replace it under a vendor deadline
- Operators who need anti-spam, anti-phishing, and anti-malware in one product on Domino, picked up by an expert who will return the call
We are not the right answer if
You are on Microsoft 365. SpamSentinel is built for Domino, not for M365. For modern Microsoft 365 mail flow, the right products are Phishing Protection, Spam Filtering, and inbox-level Visual Mail Verification.
You are on Google Workspace. Google's built-in spam and phishing protection is genuinely strong, and SpamSentinel is built for Domino in any case. Stay with what Google offers built-in for Workspace tenants. (Authentication products like DMARC Report and SPF Management still apply on Workspace.)
You are already on a path off Domino. SpamSentinel extends the operational life of the deployment you have. It does not compete with a cloud migration. If a migration is genuinely happening, the right conversation is about Tenant Migration instead.
You need a specialized DLP suite tied to a specific compliance regime. SpamSentinel is practical email security for Domino. It does not replace category-leading DLP tooling.
An expert who has actually deployed on Domino
When you contact us about your Domino environment, you talk to an expert who has actually deployed SpamSentinel on Domino servers in production. Not an SDR, not a generalist. We tell you yes or no quickly. If yes, we get to work. If your environment is not a fit, we say so and you walk away with the time you came in with.
Reference calls with existing SpamSentinel customers are available on request. Most regulated Domino customers will not allow public logo use, but they will take a phone call from a serious prospect to vouch for what we actually run in production.
Talk to an expert about your Domino environment
Same-day response. Real expert on the call. Pricing, deployment specs, and the technical questions answered directly.