Safely Test Your Sending Speed

To test how quickly you can send multiple messages through Twilio SendGrid without affecting your sender reputation, send your test messages to any address at the @sink.sendgrid.net domain.

Twilio SendGrid provides this domain so you can test relay speeds at higher volumes using your standard integration practices. All messages sent to this domain are accepted for delivery and then immediately deleted. Sending to this domain doesn't contribute to the IP warmup process if you have an account with a dedicated IP address.

If you are looking to test your API integration, you can enable the sandbox_mode in the mail_settings parameters of our Mail Send API. This will allow you to validate each parameter you include, and the structure of your JSON payload, all without actually sending a message.