Protect.
Threats stopped before the inbox.
The threats keep changing. The defense layers keep multiplying. The vendors keep raising prices. And somewhere in the middle of all that, your users still have to read their email. These are the DuoCircle products that protect inbound mail, from the gateway down to the inbox itself.
Four products, layered defense
Phishing Protection
Real-time phishing defense for inbound mail. Multi-layer threat scanning, click-time URL inspection, attachment inspection, and false-positive controls so your help desk isn't drowning. For mid-market organizations on Microsoft 365 and Exchange.
Spam Filtering
Cloud-based spam filtering with practical tunability. Catches the obvious junk, blocks malware, and lets you adjust the false-positive cases that show up in your environment. Category-leader capability at the value-tier price.
Visual Mail Verification (Verisend)
A Microsoft 365 inbox app that shows users, visibly inside the message, which emails are verified legitimate and which deserve a second look. The sixth layer of email security, where threats actually land.
HCL Notes / Domino (SpamSentinel)
Native spam, phishing, and virus protection for HCL Domino servers. Running on Domino since 2003. The product the major email security vendors stopped building for years ago, still maintained because customers still run Domino.
Five layers before the inbox, plus one inside
Email protection is a layered problem. The first five layers stop threats before the inbox: SPF, DKIM, DMARC, anti-spam gateway, anti-phishing scanner. The sixth layer, visual verification at the user level, catches the messages that look legitimate enough to bypass the first five.
Most vendors sell one or two of these layers as separate products with separate billing. DuoCircle's protection products share an engineering team and a single accountable party. When a phishing wave finds a gap, the team that closes the gap is the team that picks up the support call. For the niche cases (HCL Notes / Domino, regulated banking with KYC requirements), the same engineering team builds and supports those too.
The audience
- Mid-market IT teams that need enterprise-grade phishing and spam protection without an enterprise price tag
- Banks and financial services firms facing BEC threats where a single successful attack is catastrophic
- Organizations with active HCL Domino / IBM Notes infrastructure who can't or won't migrate to cloud email
- Compliance-driven environments (financial, healthcare, government) where email-based attacks have regulatory consequences
We're not the right answer if
You're on Google Workspace. Our Spam Filtering and Phishing Protection products are not the right fit. Google's built-in protection is genuinely strong, and we don't think we add enough on top of it to justify the spend. Stay with what Google offers built-in. (Other DuoCircle products like DMARC Report and AutoSPF still apply on Workspace.)
You need full DLP suites with regulatory-specific controls (HIPAA, GDPR, PCI). DuoCircle's protection products don't replace specialized DLP tooling.
Your built-in Microsoft 365 protection is sufficient for your risk profile. Layering DuoCircle on top is a real value-add but isn't strictly required. We'd rather you pay for what you actually need.
Talk to an expert about your email protection
Same-day response. Real expert on the call. We tell you which layers you need and which you don't.