What email addresses to use for testing?

When testing email functionality, it's important to use designated test addresses to avoid unintended consequences like deliverability issues or spam complaints.

Resend provides a set of safe email addresses specifically designed for testing, ensuring that you can simulate different email events without affecting your domain's reputation.

Many developers attempt to use domains like @example.com or @test.com for testing purposes. However, these domains are not designed for email traffic and often reject messages, leading to bounces.

A high bounce rate can negatively impact your sender reputation and affect future deliverability. To prevent this, Resend blocks such addresses and returns a 422 Unprocessable Entity error if you attempt to send to them.

To help you safely test email functionality, Resend provides the following test addresses, each designed to simulate a different delivery event:

Using these addresses in your tests allows you to validate email flows without risking real-world deliverability problems. For more help sending test emails, see our testing documentation.

Most test email addresses support labeling, which enables you to send emails to the same test address in multiple ways. You can add a label after the + symbol to help track and differentiate between different test scenarios:

• delivered+user1@resend.dev
• bounced+signup@resend.dev
• complained+newsletter@resend.dev

This is particularly useful for testing different email flows, tracking webhook responses, and matching responses with the specific email address that triggered the event.

Whether you need to confirm that an email has been sent, track engagement events, or simulate a bounce scenario, these addresses provide a controlled and predictable way to test your email integration with Resend.