# Configure FluentSMTP with Microsoft Outlook/Office Email

This is the Microsoft Entra path. If you already work in Azure Portal, the same app registration exists there: [Outlook or Office365 with FluentSMTP](https://fluentsmtp.com/docs/setup-outlook-with-fluentsmtp/).

Outlook, Hotmail, and Microsoft 365 are fine for ordinary site mail. They are a poor choice for bulk or marketing. Microsoft will throttle or lock the mailbox.

## Open the Outlook connection

1. Go to **Settings → FluentSMTP**.
2. Pick **Outlook or Office 365**, or **Add Connection** then **Outlook or Office 365**.

Fill **Sender Settings**:

- **From Email**: the Microsoft address that will send.
- **From Name**.
- **Set the return-path to match the From Email**.
- **Force Sender Name** if you want this name on every message this connection sends.

Outlook does not have **Force From Email**. The mailbox you authenticate as is the From.

Copy **App Callback URL** on that form and keep it. That URL is unique to this WordPress site. It is not `fluentsmtp.com`.

With pretty permalinks on, it looks like:

```
https://your-site.example/wp-json/fluent-smtp/outlook_callback
```

If permalinks are set to Plain, WordPress shows the REST route instead. Copy that exact string:

```
https://your-site.example/index.php?rest_route=/fluent-smtp/outlook_callback
```

Paste whichever one the form shows into Microsoft. Do not invent the pretty URL if the form shows `rest_route`.

![Outlook connection form with Client ID, tenant field, and the site App Callback URL](https://fluentsmtp.com/docs/images/outlook-connection.png)

## Register the app in Microsoft Entra

1. Sign in at [entra.microsoft.com](https://entra.microsoft.com/).
2. **Entra ID → App registrations → New registration** (older layouts use **Applications → App registrations**).
3. **Name**: `FluentSMTP`.
4. **Supported account types**: for most sites use **Accounts in any organizational directory (Any Microsoft Entra ID tenant - Multitenant) and personal Microsoft accounts**. If this app is only for one company tenant, pick that single tenant instead and fill **Directory (tenant) ID** later.
5. **Redirect URI**: platform **Web**, URI = the **App Callback URL** you copied.
6. Review the Microsoft Platform Policies linked on the form, then click **Register** if you agree.

Use your own app name and the callback copied from your WordPress site. The current account-type dropdown may shorten the option to **Any Entra ID Tenant + Personal Microsoft accounts**.

![Microsoft Entra registration form with organizational and personal accounts and a Web redirect URI](https://fluentsmtp.com/docs/images/microsoft-entra-register-app.png)

The screenshot uses the local demo address `smtp.lab`. Use the callback from your own WordPress site.

On the Overview page, copy **Application (client) ID**. That is **Application Client ID** in FluentSMTP.

## Create a client secret

1. **Certificates & secrets → Client secrets → New client secret**.
2. Add a description and an expiry you will remember (or the longest you are allowed).
3. **Add**. Copy **Value** immediately. Microsoft will not show it again. The Secret ID is not the secret.

![Microsoft Entra Certificates & secrets page with the Add a client secret panel, description, and expiry](https://fluentsmtp.com/docs/images/microsoft-entra-client-secret.png)

When the secret expires, mail stops until you create a new secret, paste it, and authenticate again.

## Fill FluentSMTP and authenticate

1. Leave **Store in Database** selected. You can tick **Disable Encryption**, or switch to **Store in wp-config.php**. Both are optional. See [Where secrets are stored](https://fluentsmtp.com/docs/fluent-smtp-settings/#where-secrets-are-stored).
2. **Application Client ID**: the client ID.
3. **Application Client Secret**: the secret **Value**.
4. **Directory (tenant) ID (Optional)**: leave empty (placeholder `common`) unless the Entra app is single-tenant. For a single-tenant app, paste the Directory (tenant) ID from Overview, or a verified domain such as `contoso.onmicrosoft.com`. Use `organizations` if work/school accounts only, or `consumers` if the registration only allows personal Microsoft accounts. Changing tenant after a successful auth means you must authenticate again.
5. Click **Authenticate with Office365**. Sign in with the mailbox you want to use. Check the app name and requested permissions, then click **Accept**. The prompt requests permission to send mail and maintain access between sessions.

![Microsoft consent prompt for FluentSMTP Docs showing Send mail as you and Maintain access permissions](https://fluentsmtp.com/docs/images/microsoft-oauth-consent.png)

6. The callback opens **Your Access Code**. Copy the code into FluentSMTP’s **Access Token** field, then click **Save Connection Settings**. Keep this code private.
7. Reopen the saved connection to confirm **Outlook / Office365 is connected**.

![FluentSMTP Outlook callback URL and connected confirmation](https://fluentsmtp.com/docs/images/outlook-connected.png)

Send a test from **Send Test Email**.

## If authentication fails

- Redirect URI in Entra must match **App Callback URL** character for character, including `http` vs `https`, and including `rest_route` if that is what the form shows.
- If the form shows `/wp-json/` and that URL 404s, permalinks or a security plugin is blocking REST. Switch permalinks to a pretty setting, or use the `rest_route` URL the form prints when permalinks are Plain.
- The Microsoft account you approve must be allowed to send as **From Email**.

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Source: https://fluentsmtp.com/docs/configure-fluentsmtp-with-microsoft-outlook-office/