A test email address allows you to test Google Workspace by receiving email. Once you verify domain ownership, each user in your domain will be assigned a test email address to receive mail. Test email addresses have '.test-google-a.com' appended to the end. Your test email address will look like this: user.name@your_domain.test-google-a.com.
Use a test email address
You don't use test email addresses for sending mail. You can use them to test mail delivery or set up a pilot for your users. You can continue using them for as long as you need. Once you verify domain ownership, you can send mail from your Google Workspace email account. Mail sent from your account won't include test-google-a.com.
Remove the test email addresses when you're done with them
To remove the test email addresses for your users, follow the instructions to remove the domain alias your_domain.test-google-a.com.
Note: Unlike domain aliases you add yourself, you can't remove the test domain alias. De-activating it stops users from receiving email at their test email addresses.