You can start testing schemas in email today. All schemas that you send to
yourself (from `username@gmail.com` to `username@gmail.com`) are displayed in
Google products.

When you're ready to launch marked-up emails to your users, register with
Google:

- Make sure that you meet all the guidelines and requirements listed below.
- Send an email from your production servers (or a server with similar `DKIM`, `SPF`, `From:`, and `Return-Path:` headers) including the markup or schema to `schema.whitelisting+sample@gmail.com`. Google checks that you comply with all the guidelines and requirements listed in [registration guidelines](https://developers.google.com/workspace/gmail/markup/registering-with-google#registration-guidelines).
  - If you send a test or blank email, an email that doesn't contain a schema, or if you don't send an email for review, your application is discarded.
  - Make sure that the markup is correct before sending the email. For more details, see [Test your schemas](https://developers.google.com/workspace/gmail/markup/testing-your-schema). Ensure the email passes the [Email Markup Tester](https://www.google.com/webmasters/markup-tester/) without errors, and include as much data as possible.
  - Gmail removes all markup when forwarding an email. Don't forward the email; send it directly.
- Fill out the [registration form](https://docs.google.com/forms/d/e/1FAIpQLSfT5F1VJXtBjGw2mLxY2aX557ctPTsCrJpURiKJjYeVrugHBQ/viewform?pli=1).

## Registration guidelines

To process the schemas that you send, you must meet the following guidelines:

### Email sender quality guidelines

- Emails must be [authenticated using DKIM or SPF](https://support.google.com/mail/answer/81126#authentication).
- The top-level domain (TLD) of the SPF check or DKIM signature must match the TLD of your `From:` email address.
  - For example, if you use `From: user@example.com`, the DKIM or SPF must be for `example.com` or `sub.example.com`.
  - Gmail only checks the SPF on the domain of your `Return-Path:` email. If you only rely on SPF and not DKIM, your `Return-Path:` email must match the TLD of your `From:` email.
  - To quickly check if your SPF or DKIM settings are correct, see [Email authentication](https://support.google.com/mail/answer/81126#authentication).
- Emails must come from a static email address, such as `user@example.com`.
- Emails must follow the [Prevent mail to Gmail users from being blocked or sent to spam](https://support.google.com/mail/answer/81126) guidelines.
- Consistent history of sending a high volume of mail from your domain (order of hundreds of emails a day minimum to Gmail) for at least a few weeks.
- A very low rate of spam complaints from users.

### Actions and schema guidelines

- The highest-fidelity action available should be used. For example, if an interaction can be achieved by an in-app action (one-click, RSVP, review), that must be used. For more complex interactions, go-to actions can be used.
- Actions should be used for transactional mail where a high interaction rate is expected. They shouldn't be used on promotional bulk mail.
- Go-to actions:
  - Must deep link into the specific page on which the action can be performed.
  - Label of button needs to reflect a clear action to be taken and must be true to the page the user is going to.
  - Label of action shouldn't contain punctuation or all caps. Must be short and concise.
  - If an in-app action can be used for your use case, you must use the in-app action and not the go-to action (for example, "Verify Email Address" or "Review" should use in-app actions).
  - Go-to actions are approved only for specific high-value use cases with high interaction rates (such as flight check-in and shipment tracking links).
- Low failure rate and fast response for services handling action requests.