Best Email API Providers for Developers in 2026: SendGrid vs Postmark vs Mailgun vs SES vs Resend

Your email provider sticks with you longer than most technical decisions. Courier handles notification infrastructure for thousands of teams, so we went deep on the six email providers that show up most: SendGrid, Postmark, Mailgun, Amazon SES, Resend, and SMTP. This guide covers real API primitives, actual code from each provider's docs, Courier integration examples with provider overrides, and an honest read on where each developer experience holds up and where it breaks down. We also asked Claude to review every API and tell us which one it would wire up first. The answer surprised us.

I Built an AI Board Member in Cursor. Here's How.

Every month I send a board update—and every month I wish someone would tell me what’s wrong before it goes out. Investors are busy, feedback comes late, and most people soften the punch. So I built an AI board member using Cursor Rules: three markdown files, a basic project layout, and no plugins. Drop in your board deck, get an immediate review, and walk into the meeting with fewer surprises.

Top 8 Customer Engagement Platforms for Product-Led SaaS in 2026

Comparing Courier, Iterable, OneSignal, Braze, Customer.io, Knock, Novu, and SuprSend across orchestration, developer experience, and infrastructure primitives for product-led SaaS.

What are transactional notifications? Transactional email examples, transactional push, and more.

Transactional notifications are automated messages triggered by user actions or system events, like password resets, order confirmations, and payment alerts. Unlike marketing messages, they require no opt-in and have legal protections under CAN-SPAM. This guide covers what transactional notifications are, how they work across email, SMS, and push channels, real-world examples for each, and how to stay compliant. Whether you're building your first notification system or auditing an existing one, this breakdown will help you understand what belongs in each category and how to route messages correctly.

What's the Difference Between Omnichannel & Multichannel

Most teams say "omnichannel" when they mean "multichannel," and in most cases the distinction doesn't matter much. But if you truly want to provide an exceptional customer engagement experience you should know the difference. Both involve sending messages across email, push, SMS, Slack, and in-app. They terms diverge when those channels know about each other. Multichannel means you can reach users on multiple channels. Omnichannel means those channels share state, so a user who reads a push notification won't get the same message via email an hour later. This guide breaks down the real distinctions, when the difference actually matters, and which messaging platforms deliver true omnichannel coordination.

A Resilient Notification Strategy for Regulated Industries

Notification compliance isn't a legal checklist—it's an infrastructure problem. In 2026, Reg E deadlines, HIPAA content rules, and TCPA consent requirements dictate your system architecture. This guide breaks down the engineering constraints of regulated notifications for fintech, healthcare, and insurance. Learn why hard-coded deadlines fail, how "alert without disclosing" works in practice, and why the smart escalation pattern (Push → SMS → Email) is the only way to satisfy both user urgency and regulatory documentation. Build systems that absorb complexity, not application code that breaks every time a state law changes.