How to Test Emails in Node.js
Testing emails in Node.js with Nodemailer and an SMTP sandbox: catch the email, wait for it in a test, follow the link, run it in CI, check it in Outlook.
Honza Charamza
News, guides and email testing notes
Insights, tutorials, and updates about email testing, SMTP development, and the Mailloop platform.
Single Prompt To Perfect Email On Every Platform
How to give an AI agent a single prompt and get an email that renders correctly in every client, checked against a screenshot of each one.
Honza Charamza
See How Your Email Renders in Every Client
Capture an email in a sandbox and see it the way Gmail, Outlook and other clients show it, in light or dark, on a phone or a desktop.
Honza Charamza
Best email testing tools for developers in 2026
8 email testing tools ranked for 2026: Mailloop, Mailtrap, Mailpit, smtp4dev, Mailosaur, Ethereal, MailSlurp and MailHog, with real prices and free tiers.
Honza Charamza
Mailloop for AI Agents
Mailloop now has an MCP server and an Agent Skill, so your coding agent can create a sandbox, trigger a send, wait for the email and assert on it from the chat.
Honza Charamza
Webhooks Are Live
Sandboxes can now push email events to your endpoint the moment they arrive, as an HTTP POST signed with HMAC-SHA256 and retried if it fails.
Honza Charamza
Mailloop API and JavaScript SDK Now Available
We've released a public API and JavaScript SDK for Mailloop. Create sandboxes, fetch emails, and automate email testing directly from code.
Honza Charamza
Introducing Mailloop: Our Take on Email Testing
We're launching Mailloop, an SMTP sandbox for testing emails during development. If you've used email testing tools before, you know what this is about.
Honza Charamza