Blog
Notes on email, OTPs, and testing.
Long-form pieces on building reliable email-receiving infrastructure, OTP UX, and what we learned operating an inbox at scale.
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Agent email at scale: 50 parallel signups without breaking
What breaks when an AI agent has to sign up for 50 SaaS products in parallel, verify each one, and extract the trial key. The patterns that work and the rate limits to plan for.
by catchotp team
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The disposable email problem in 2026
Why disposable email domains exist, why they keep getting blocked, what abuse looks like in 2026 — and what makes a programmable inbox different.
by catchotp team
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Email testing in CI without burning real inboxes
How to wire programmable email into GitHub Actions, CircleCI, and GitLab — with parallelization, secret scoping, and concurrency that does not blow up at 50 workers.
by catchotp team
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A Mailosaur alternative for OTP testing in 2026
An honest comparison: where Mailosaur friction shows up, what catchotp does differently for OTP/email testing, and when each tool is the right pick.
by catchotp team
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Building a programmable email API: lessons from catchotp
How we designed the catchotp inbound pipeline on AWS — SES quirks, why we chose EventBridge, and the trade-offs we'd make differently.
by catchotp team
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How to test SMS OTP flows in 2026
End-to-end guide to testing SMS one-time-password flows with Twilio, Telnyx, and Vonage receivers — and why an email-OTP primitive is often a better proxy.
by catchotp team
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Stripe webhook testing without ngrok
Test Stripe webhook handlers in CI with no public endpoint. Use catchotp to capture Stripe's email-based test events and EventBridge to fan out to your handler.
by catchotp team
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What is programmable email? A developer's definition
Programmable email is a category of receive-side email infrastructure exposed through an API: create an inbox, wait for a message, parse the result. Here's the full definition.
by catchotp team
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How AI Agents Handle Email: The MCP Way
Building AI agents that can sign up to services, verify accounts, and handle email-based flows — using the Model Context Protocol.
by catchotp team
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Best Email Testing Tools for Developers in 2026
A developer's guide to email-testing solutions: when to use disposable inboxes, when to upgrade to programmable email, and what's worth paying for.
by catchotp team
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How to E2E Test Sign-Up Flows With Real Emails (Without the Pain)
Stop mocking email in your E2E tests. Use real inboxes, real OTP delivery, and real waiters — without polluting your team inbox.
by catchotp team
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Programmable Email vs Disposable Email: A Developer's Guide
What's the difference between disposable inbox sites and programmable email APIs? When to use each, with code examples.
by catchotp team
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How to Test OTP Flows in 2026: A Complete Guide
End-to-end guide to testing one-time-password flows in Node.js, Python, Go, and curl. With Playwright and Cypress integrations.
by catchotp team