How to Test Email Notifications in Vibecoded Apps

Use a service like Mailtrap, Mailhog, or Ethereal to capture emails during development without sending real messages. Trigger every email your app sends: welcome emails, password resets, payment receipts, and notifications. Verify that each email arrives promptly and is sent to the correct recipient.

Check sender information — the from address, reply-to address, and sender name should be correctly configured. AI-generated email code often uses default or placeholder sender addresses that hurt deliverability. Also test that unsubscribe links are present where required by law (CAN-SPAM, GDPR) and that they actually work.

Open each email in multiple clients: Gmail, Outlook, Apple Mail, and a mobile mail app. Email rendering varies dramatically between clients, and AI-generated HTML templates often use CSS features that only work in webmail clients. Test that images load, layouts are not broken, and text is readable in all clients.

Verify that dynamic content is populated correctly. AI-generated email templates commonly have placeholder text that was never replaced ("Hello {{username}}"), missing data that renders as 'undefined' or 'null', or incorrect personalization. Test with various data states including users with long names, no profile picture, and special characters.

Click every link in every email and verify it goes to the correct destination. AI-generated emails frequently contain hardcoded localhost URLs, staging environment links, or broken relative URLs. All links should use absolute URLs and point to your production domain.

Test that action links work correctly: email verification links should verify the account, password reset links should open the reset form, and magic login links should log the user in. Verify that time-sensitive links expire appropriately and show a clear message when expired, not a confusing error page.