Brad Slavin is a manager at DuoCircle, an email security company. He writes here about business, the ideas in Tim Ferriss's 4-Hour Work Week, technology, and living deliberately.
I started writing at bradslavin.com years ago as a place to think out loud about the ideas that shaped how I build and live — lifestyle design, startups, the technology I was working on, and the occasional detour into health and whatever else had my attention. This is the archive of that writing, brought forward to a faster, simpler home.
Now
These days I focus on email security and deliverability at DuoCircle, and I'm writing again — short, practical notes on building software businesses, working smarter instead of longer, and the tools I actually use. If that's your world too, let's connect on LinkedIn.
What I write about
- Entrepreneurship
- SaaS
- Email Security
- Lifestyle Design
- Product Strategy
What we build at DuoCircle
I work on email security and deliverability at DuoCircle. Here are the products my team builds — tools that keep email authenticated, deliverable, and safe:
- DuoCircle — The email security company behind these products — spam filtering, email forwarding, outbound SMTP, and hosted email protection for small businesses.
- DMARC Report — DMARC monitoring and reporting — analyze aggregate and forensic reports and move your domains toward enforcement (p=reject).
- AutoSPF — Automatic SPF flattening that keeps your SPF record under the 10 DNS-lookup limit and prevents PermError.
- Phish Protection — Cloud email security against phishing, spoofing, and business email compromise (BEC) for Microsoft 365 and Google Workspace.
- NuReply — AI cold-email personalization and inbox warm-up tools that build sender reputation and land emails in the inbox.
- InboxIssue — Email deliverability testing for corporate inboxes — test against Google Workspace, Office 365, and enterprise security filters.
- Mailflow Monitoring — Round-trip SMTP and IMAP monitoring that alerts you the moment your email stops flowing.
- unsent.dev — Developer email delivery platform — REST API, SMTP relay, and SDKs for transactional and marketing email at scale.