You run HCL Domino, formerly IBM Notes, and you have heard for a decade that you should migrate. Maybe you cannot, maybe you choose not to. 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.
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.
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.
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.
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.
Attachments and message bodies scanned against current threat signatures. Built-in macro blocking focuses specifically on macro-bearing attachments, one of the most persistent delivery patterns in email-borne malware.
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.
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.
SpamSentinel starts at $780/year for 6 seats and scales to $40,000/year for 2,000 seats. Per-seat annual licensing, 12 published tiers, minimum 6 seats.
DMARC reporting included on every plan. Direct replacement for ESET Mail Security for IBM/HCL Domino. Above 2,000 seats: contact sales.
SpamSentinel is per-seat annual licensing for HCL Domino. Starts at $780/year for 6 seats ($130.00/seat/year) and scales to $40,000/year for 2,000 seats ($20.00/seat/year). 12 published tiers, minimum 6 seats.
Annual subscription only. SpamSentinel is sold by seat count once per year. No monthly billing option.
6 seats. SpamSentinel does not sell smaller-than-6-seat tiers because the operational overhead per Domino install does not scale below that threshold.
Yes. SpamSentinel is a native HCL Domino product (since 2003) and the direct migration path for customers on ESET Mail Security for IBM/HCL Domino, which reached end of life on July 31, 2026. Includes DMARC reporting on every plan.
SpamSentinel is built specifically for HCL Domino. For Microsoft 365, Exchange, or Google Workspace, the right DuoCircle product is Phishing Protection (per-user) or Spam Filtering Gateway (per-domain).
Above 2,000 seats is custom volume pricing — contact sales for a quote. The published catalog tops out at the 2K tier.
If you can use the online checkout, the price you see is the price you pay.
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.
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.
Tell us your Domino version, your user count, and what is currently running. Same-day response with pricing, deployment specs, and the technical questions answered directly.