Mailnest

Open your email client, point SMTP to Mailnest, and start shipping safe test messages immediately. Instead of creating throwaway inboxes or muting real recipients, route all non‑production traffic into a single workspace. Spin up a dummy SMTP endpoint, drop the credentials into your app or staging config, and every message is intercepted—no accidental sends to customers. Organize by project or environment, add tags for campaigns or features, and invite teammates so engineering, QA, and marketing can review the same stream without forwarding chains or screenshots.

Use the viewer to audit what actually goes out. Inspect HTML and plain‑text bodies side by side, confirm the subject and preview line, and scan headers for reply‑to, return‑path, and authentication fields. Open raw MIME to validate multipart boundaries, inline images, and attachments. Click through links to verify replacements, UTM parameters, and unsubscribe routes (with safe URLs). Check personalization by triggering flows with different users—see how names, dates, totals, and locale switches render without seeding databases or creating extra test accounts. When something looks off—a broken button in a reset email, a missing invoice PDF—pin the message, share a link with context, and iterate on the template until it’s right.

Automate the checks developers care about. In CI, send a message from your test suite to Mailnest and assert on the body, headers, and attachments through the API. Block a release if a variable is undefined, a link is empty, or the plain‑text fallback is missing. Run failure simulation to harden retry logic: toggle temporary 4xx responses, trigger 5xx bounces, throttle connections, or reject invalid recipients, then verify backoff and alerting. Exercise edge cases—long subjects, large attachments, non‑ASCII characters, or template switches—without clearing test data or minting new IDs. Search the inbox, compare versions across builds, and export raw content for snapshot tests. With routine tasks handled, your team spends time fixing issues instead of chasing them, and every workflow—from onboarding to receipts—ships with confidence.