Email experts,
not sales reps.
Since 2014.
A family of specialized email products covering authentication, protection, delivery, and routing. About 90% of category-leader capability at roughly half the cost, backed by experts who own the outcome. Twelve years in operation, over 50,000 organizations.
Third-party-verifiable trust posture
Posture published at trust.duocircle.com. SOC 2 reports under the publicly-published Bonterms NDA.
Email infrastructure, in four groups
Specialized products covering authentication, protection, delivery, and routing. Each one built because a customer asked for help that the existing vendors wouldn't engage with at their tier.
Authenticate
SPF Management (AutoSPF), DMARC Reporting (multi-region G2 Category Leader), free Mail Flow Monitoring, BIMI hosting once you have a VMC.
- AutoSPF
- DMARC Report
- Mail Flow Monitoring
- BIMI hosting
Protect
Phishing Protection, Spam Filtering, Visual Mail Verification (Verisend for M365), and SpamSentinel for HCL Notes / Domino.
- Phishing Protection
- Spam Filtering
- Verisend
- SpamSentinel
Deliver
Outbound SMTP (outboundsmtp.com), Developer Email API (unsent.dev), Inbox Placement Testing (InboxIssue), Cold Email Outreach (NuReply).
- Outbound SMTP
- unsent.dev
- InboxIssue
- NuReply
Route
Alumni Forwarding for universities, Tenant Migration for M365 and Workspace cutovers, Email Forwarding, Backup MX, and Message Replay for per-message recovery.
- Alumni Forwarding
- Tenant Migration
- Email Forwarding
- Backup MX
About 90% of the capability. About half the price.
The pattern holds across every category we compete in: enterprise security, DMARC reporting, transactional sending, cold outreach. We give you the capability that actually moves your email program. When you genuinely need the other 10%, we will tell you, and we will point you somewhere better.
Click-time URL inspection, BEC defense, impersonation. Half the price, no procurement gauntlet.
Compare →Multi-region G2 Category Leader. Free tier for one domain. Volume-based pricing.
Compare →Operating since 2014. Free up to 1,000 emails per month, no credit card.
Compare →Bring your own mailbox cold outreach. Built-in deliverability hygiene.
Compare →See the full set on our comparisons page.
One product brings them in. The rest of the portfolio keeps them.
A team comes to AutoSPF to fix an SPF record that's blowing the 10-DNS-lookup limit. The immediate problem gets fixed. A few weeks later they realize the bigger issue isn't SPF flattening, it's that their domain has no DMARC enforcement and they don't actually know who's sending mail as them. So they add DMARC Report alongside AutoSPF, and finally see the full picture.
A business signs up for Outbound SMTP's free tier because their office copiers stopped authenticating to Office 365 and can no longer send scan-to-email. The copiers come back online. A few weeks in, the IT team notices that the mail our relay is putting out actually shows up properly SPF and DKIM aligned. They ask what else we can help with. Turns out they've had a long-running email-deliverability problem nobody else has been able to fix. We work that one next.
A Phishing Protection customer keeps catching the same impersonation pattern at the gateway and asks why the bad mail keeps coming. The answer is upstream: their DMARC posture is at p=none (anyone can spoof their domain at will) and their SPF is at ~all (softfail, so even authenticated mail isn't strictly enforced). They add DMARC Report to push toward enforcement, the impersonation rate drops, and the expert running the rollout is the same one who's been answering their support tickets for years.
The portfolio looks deliberate now because it is, just not top-down deliberate. Every product is a yes to a customer who couldn't get one elsewhere. The shape only becomes visible looking back.
“DuoCircle is easy to work with and willing to make it happen. Their solution is solid.”
Most enterprise customers prohibit logo use to keep SaaS vendors from leveraging their brand. Customers who have explicitly authorized attribution include Arakÿta and eXp Realty (NASDAQ-traded).
The proof, plainly
Third-party-verifiable trust signals plus the operating principles that have run the company since 2014.
SOC 2 Type 2 since 2022
Audited annually under the AICPA Trust Services Criteria (Security, Availability, Confidentiality, Processing Integrity). Hancock Askew & Co performs the audit. The Bonterms Mutual NDA is published publicly so prospects review it before requesting the report.
Email experts, not sales reps
When you call DuoCircle, the person on the call is the person who will solve the problem. No SDR funnel, no multi-tier escalation queue. We tell you yes or no quickly. If yes, we get to work.
Customer accolades, earned not bought
Hundreds of verified reviews across the portfolio at a 4.8-star aggregate. Multi-region category-leadership recognition. CSA STAR Registry listings for six services. The accolades have been arriving for years; you can read the full picture in our reviews.
Free is the door
Outbound SMTP free up to 1,000 emails/month, no credit card required. DMARC Report has a free tier for one domain. Mail Flow Monitoring is fully free since 2018. Become a customer at zero cost and let us help with whatever else comes up.
Friction-free trust posture
Pricing on the product sites. SOC 2 reports under a publicly-published Bonterms Mutual NDA. Free tiers wherever they fit. No NDA gauntlet, no procurement runaround.
Reference calls beat logos
Most of our enterprise customers prohibit logo use to keep SaaS vendors from leveraging their brands. Those same customers will take a phone call from a serious prospect to vouch for DuoCircle directly.
Talk to one of our customers
Most of our enterprise customers prohibit logo use to keep SaaS vendors from leveraging their brand. They will, however, take a phone call from a serious prospect to vouch for what we actually do in production. Tell us you're serious and we'll set one up.
Request a reference call →Did right by you
When prospects come to us for an evaluation, we give them a fair technical answer. Sometimes that answer is "you don't actually need what we sell." Sometimes it's "the right answer is somebody else, here's why." Sometimes it's "yes, this is a fit, here's how it would work." All three happen, in roughly equal measure.
The standard we hold ourselves to is simple. If, sometime in the future, a neutral third-party technical expert looks at our recommendation in retrospect, they should be able to say "DuoCircle did right by you." That principle outweighs any individual sales conversation.
The honest "look elsewhere" stance shows up on every product page. We'd rather walk away from a bad fit than sell into one. The customer base we have today, more than 50,000 organizations across twelve years, is built on that operating principle, not in spite of it.
Talk to an expert about your email infrastructure
Same-day response. Real expert on the call. We tell you yes or no quickly, and we'll point you somewhere better when we can.