[Tadrill] DMI (Direct Message Injection) Settings (Google Workspace)

Action summary

This article explains the procedure to activate the DMI (Direct Message Injection) feature in Tadrill.

What is DMI (Direct Message Injection)?

DMI is a feature that uses Microsoft / Google APIs to directly create training emails in users' mailboxes.
With this, it is no longer necessary to register a whitelist in gateway-type email security products, and you can use your own domain as the sender.
Additionally, for the sender domain of training emails, you can use your own domain registered with HENNGE.

* There are notes regarding the DMI feature, such as it cannot be used for group addresses.
Please review the notes below and, if you wish to use the DMI feature, follow the procedure in this article.
If you do not perform this setup, the SMTP delivery method (delivery via mail server) will be applied.

Notes

1. The DMI feature is available to customers subscribed to the HENNGE One Pro plan or the standalone Tadrill plan.
2. The content of this article is based on the product specifications as of May 2026 and may be subject to change without notice.
3. If there are trainings that are not started or in progress, the DMI feature cannot be turned off.
   Please refer to the following article to check the training status.
   [Tadrill] How to check training results
4. Training cannot be sent to group addresses with DMI.
   When DMI is enabled for a tenant, group addresses cannot be selected as targets when creating trainings.
   * If you need to send training to a group address, please temporarily disable the setting as a workaround.
   As noted in Notes 3, please be careful about the timing of changing the settings.
5. During training, users may reply to training emails.
   Therefore, if you use your own domain as the sender domain, please note the following two points:
   1. If the email address exists: You may receive inquiries via replies.

   2. If the email address does not exist: Since reply emails will not be delivered and errors will occur, the reputation of your domain may decrease.

      For the above reasons, if you conduct training from your own domain, we recommend creating an email address to receive replies.

6. Only for email security products installed in the email sending route, such as gateway-type products, whitelist registration is not required.
   * If you are using cloud-based or endpoint-based products, you need to register a whitelist.
   [Tadrill] Whitelist registration for email security services

Procedure

Google Workspace Administration Settings

1. From the Google Workspace Administration, go to [Security] – [Access and data control] – [API controls].
2. On the [API controls] screen, click [Manage domain-wide delegation] under [Domain-wide delegation].
3. On the [Domain-wide delegation] screen, click [Add new].

4. On the [Add a new client ID] screen, enter the following values and click [Authorize].
   * Due to Google specifications, it may take up to 24 hours for changes to take effect.
   Client ID:

   103361117025797654244

   OAuth scopes (comma-separated)

   https://www.googleapis.com/auth/gmail.insert

5. Return to the [Domain-wide delegation] screen and confirm that the [Tadrill DMI] entry has been added.

Tadrill Settings

1. From the Administration, go to [Integrations].

   

2. On the [Integrations] screen, click [Google Workspace DMI Settings] – [Continue].

   

3. You will be redirected to the [Enable DMI] screen. Review the content and click [Create].
   * A test email will be sent to the email address displayed on this screen after DMI is activated.

   

4. Confirm that "Connected" is displayed to the right of [DMI Settings].
   You can toggle the feature on or off using the button at the bottom.

   

5. Once you have confirmed that an email with the subject "Test DMI" has arrived in the mailbox of the user who performed this procedure, the setup is complete.