Set up Microsoft 365 email with Regal Send

Updated September 22, 2026

Microsoft 365 setup wizard prerequisites#

The Microsoft 365 setup wizard in Regal Send connects WordPress to the Microsoft mailbox you authorise. Before you begin, make sure you can create or edit an app registration in Microsoft Entra and can sign in to the mailbox that should send your site emails.

  • Use an HTTPS WordPress site with the standard path-based REST API available.
  • Use the mailbox that will send messages, or a mailbox with permission to send as the configured From Email address.
  • Keep the Microsoft Entra browser tab open while you complete the wizard.

Run the Microsoft 365 setup wizard#

  1. In WordPress, go to Regal Send > Integrations, select Microsoft 365 / Outlook, then choose Use guided Microsoft setup.
  2. Copy the Redirect URI shown by Regal Send. In Microsoft Entra, create an App registration and add that exact URI under Authentication as a Web redirect URI.
  3. Open API permissions, add Microsoft Graph, choose Delegated permissions, then add Mail.Send. Regal Send does not require application-wide Mail.Send permission.
  4. Create a client secret under Certificates & secrets. Copy the secret Value, not its Secret ID, and enter it with the Application (client) ID in the wizard.
  5. Choose account types that match your Entra app registration. If you restrict the app to one organisation, enter its tenant ID or verified tenant domain.
  6. Set the From Email and From Name. The From Email should be the authorised mailbox or an address it is allowed to send as.
  7. Select Save and connect Microsoft. Sign in to the sending mailbox and approve the requested consent.
  8. When Regal Send shows Connected, choose Send test email and confirm that Microsoft accepts it.

Resolve common connection problems#

  • Not configured: check the Application (client) ID, secret Value and HTTPS callback requirement.
  • Authentication problem: reconnect the mailbox. This is also appropriate after a secret is replaced or consent is revoked.
  • Microsoft rejects the sender: compare From Email with the signed-in mailbox. Shared mailboxes commonly need the corresponding Exchange send-as permission.
  • Test email fails: use the safe diagnostic message in Regal Send, then confirm the app audience, delegated permission and mailbox authorisation.

For current Entra console steps, see the Microsoft app registration guidance and the Microsoft Graph Mail.Send permission reference.

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