Sean Dudgeon

Posts by Sean Dudgeon

Founder of Rythm

Sean is the founder of Rythm, a dual-layer deterministic email filter for Gmail and Outlook. He writes about inbox protection, economic filtering, and building on open protocols.

Email Protection

How to Defend Your Inbox From Phishing in 2026: A Realistic Guide

Most phishing defense advice is outdated. Here's what actually works in 2026, across individuals, small teams, and the structural layer nobody talks about.

Email Protection

Nonprofit Email Security Without the Enterprise Price Tag

Donor impersonation, grant fraud, board spoofing. Nonprofits carry every threat large organizations do, on a fraction of the budget. A $1.65 answer.

Open Protocols

Is a Cover Charge Just Spam Tax With Extra Steps?

Spam tax, email postage, and sender authentication have all been proposed. None stuck. Here is why the Rythm cover charge is structurally different.

Building in Public

What Your Senders Actually See: The Default Rythm Verification Email

The #1 fear before turning on an email paywall: 'will my contacts think I'm rude?' Here is the actual default message Rythm sends.

Email Protection

One Agency Inbox. Dozens of Client Accounts at Risk.

Agency inboxes sit between attackers and every client platform you touch. One phishing click can cascade. A structural filter for small agencies.

Inbox Psychology

Why We Don't Use AI to Fight AI Phishing

Every email security vendor is racing to use AI against AI phishing. Rythm goes the other direction. Here is why intention beats content.

Use Cases

Will My Prospects Be Annoyed by the Cover Charge? A B2B Reality Check

The most common B2B hesitation before turning on Rythm: won't the paywall chill my pipeline? Here's the honest breakdown by sender type.

Open Protocols

Why Rythm Isn't a Cryptocurrency Service (Even Though It Uses Cashu)

Rythm uses Cashu and Lightning under the hood. That does not make it a crypto product. Here is the clean category disambiguation.

Building in Public

What Happens to a Filtered Email That Was Actually Important?

The loss-aversion question every new Rythm user asks. Here's the honest answer: nothing is deleted, everything is rescuable, and the system is fail-open.

Email Protection

What Is the Best Way to Stop Spam Emails in 2026?

If you googled this, you probably tried the obvious things. Here is what actually works in 2026, including the last line of defense most guides miss.

Email Protection

One Fake Subcontractor Invoice. The Right Letterhead. The Wrong Bank Account.

Invoice fraud is rampant in construction. Every job brings new contacts, which is what attackers count on. A structural filter for a fast operation.

Email Protection

Small Healthcare Practices and the Email Breach Problem

Average healthcare email breach: $10.93M (IBM). Average small practice IT budget: near zero. A structural filter layer that costs less than dinner.

Use Cases

Every Missed Email Is a Missed Invoice: Rythm for Freelancers and Solo Consultants

Your best client inquiry last month was buried under outreach spam. Here's how to filter your inbox without missing the lead that pays rent.

Use Cases

Predatory Journals, Fake Conferences, and the Academic Inbox

Your .edu address is on every paper you've published. Predatory journals, fake conferences, and scammers know. A structural filter for research inboxes.

Email Protection

Evaluating Rythm: A Security & Architecture Guide for IT Teams

Security and architecture guide for IT teams evaluating Rythm. Data handling, OAuth security, attack surface analysis, and compliance.

Email Protection

Real Estate Wire Fraud Starts in the Inbox. A Bouncer Belongs There.

Wire fraud drained real estate of $446M in 2023. Every attack starts with one email. Here's how to put a bouncer on the inbox where it begins.

Use Cases

Rythm for Podcasters and Speakers: Your Next Booking Is Buried Under 47 PR Pitches

Podcast hosts and keynote speakers get flooded with PR pitch spam. Here's how to make sure the real booking email is not the one you miss.

Use Cases

Your Git Commit Email Is Public Forever. Your Inbox Doesn't Have to Suffer for It.

Every commit you've ever pushed doxxed your email. Here's how to keep recruiters, vendors, and supply chain probes out without blocking real contributors.

Open Protocols

The Two Missing Pieces of the Internet

The internet solved communication. It never solved identity or value exchange. AI is exposing that gap. Here's why open protocols are the only durable fix.

Open Protocols

The Natural State of Things

The systems that endure are not the ones we manage. They are the ones we let learn. An essay on resilience, fragility, and what nature already knows.

Use Cases

Why High-Net-Worth Individuals Need an Inbox Bouncer

High-net-worth individuals are 42x more likely to be targeted by email attacks. Your home has security. Your inbox has nothing.

Use Cases

Rythm for Creators: Stop Fake Brand Deals Before They Reach Your Inbox

Creators with public emails get dozens to hundreds of unsolicited messages a day. Fake sponsorship emails now carry malware. Here's a structural fix.

Use Cases

Rythm for Journalists: Protect Your Inbox Without Losing Your Sources

Journalists are among the most targeted people on earth for email phishing. Your inbox needs a door that real sources can still walk through.

Use Cases

Email Protection for Insurance Agencies: A Layer That Doesn't Require an IT Department

Insurance agencies handle sensitive client data with almost no IT security infrastructure. Here's a layer that changes the math.

Use Cases

Email Security for RIA Firms: Why Your Custodian Workflow Is Your Biggest Vulnerability

Your firm's email connects to custodian platforms managing millions. One spoofed wire instruction can't be undone.

Use Cases

Email Security for Financial Advisors: Why Filters Aren't Enough in 2026

Financial advisors are the #1 most-phished profession. A single compromised email can redirect millions. Here's a fix.

Use Cases

Protecting Your CPA Firm's Inbox During Tax Season

Tax season is a phishing kill zone. IRS impersonation, fake client portals, W-2 harvesting, all targeting your firm's inbox.

Use Cases

Why Solo Attorneys Need an Inbox Bouncer

29% of law firms have been breached. Solo attorneys are most vulnerable: most exposure, least infrastructure. Here's a structural fix.

Inbox Psychology

The Only Room Without a Door

Every space in your life that matters has a boundary. Your home, your office, a restaurant, a concert. Your inbox has none. What if it just had a door?

Comparisons

Rythm vs. SaneBox: Economic Filtering vs. AI Sorting

A transparent comparison of Rythm and SaneBox. Two different philosophies for inbox management: deterministic economics vs. AI prediction.

Comparisons

Rythm vs. Hey.com: What's Different and Who Each Is For

A transparent comparison of Rythm and Hey.com from the Rythm team. What's different, where Hey wins, and who each product is built for.

Comparisons

How Rythm Fits Into the Email Protection Landscape

The email protection landscape is shifting. Here's how we see the major approaches, where existing tools excel, and why we built something different.

Building in Public

How It Actually Works Under the Hood

How does a web app process payments between strangers without holding anyone's money? Here's the exact flow, from Lightning invoice to token redemption.

Building in Public

How Rythm's Non-Custodial Architecture Works

A technical deep dive into how Rythm verifies payments without holding funds, storing proofs, or reading email content. Cashu ecash + Lightning.

Building in Public

Why We Chose Deterministic Over Probabilistic Email Filtering

Every email filter uses AI to guess. We built one that doesn't guess at all. Here's the technical rationale behind Rythm's binary approach.

Use Cases

Rythm for Founders: Email Protection Without an IT Department

Founders get 50+ unsolicited emails a day. Enterprise security costs $3-8/user/month and requires IT. Rythm starts at $1.65/month and takes 12 minutes.

Use Cases

How to Stop Cold Emails Without Missing Real Opportunities

Cold emails are overwhelming your inbox. Here's how to filter them out without accidentally missing the one that actually matters.

Inbox Psychology

All Muscle, No Curiosity

A good bouncer checks the list, does the job, and forgets you walked in. That's how Rythm handles your incoming mail. Here's exactly what that means.

Inbox Psychology

Rules, Not Guesses

Most inbox tools analyze, score, and predict. They're wrong often enough to make you check anyway. What if your filter just followed rules instead?

Inbox Psychology

What Is Economic Email Filtering? The Complete Guide

Economic email filtering charges unknown senders a small fee to deliver their message, replacing AI guesswork with simple economics. Here's how it works.

Email Protection

5 Types of Phishing Emails That Fool Gmail in 2026

Gmail catches 99.9% of phishing. These are the types that get through, and why they're getting harder to spot.

Email Protection

Business Email Compromise: The $2.7 Billion Threat Your Spam Filter Ignores

BEC attacks cost businesses $2.7 billion in 2023. They bypass every spam filter because they look exactly like real email. Here's what actually helps.

Email Protection

The Big Day

Phishing doesn't work on careless people. It works on your best employee, on their busiest day, when their guard is naturally down.

Email Protection

Why Your Gmail Spam Filter Isn't Enough Anymore

Gmail catches 99.9% of spam. That sounds great until you realize what the other 0.1% looks like in 2026, and why the miss rate is climbing.

Inbox Psychology

Your Attention Has a Price. Email Is the Only Place That Ignores It.

Every platform monetizes your attention, except email. What happens when the most exploited communication channel finally gets a price tag?

Inbox Psychology

Your Attention Is Your Life

We measure attention in minutes. But attention isn't time. It's the lens that shapes every decision you make. Most of us give it away without choosing to.