---
title: "Configuring the Outlook Add-in in Domain Settings"
slug: "clone-outlook-add-in-domain-settings-with-scenarios-and-best-practices"
description: "Configure the Opensense Outlook Add-in in Domain Settings: signature insertion, inline images, Internal Domains, editable fields, and From Switching."
updated: 2026-08-21T15:43:19.000Z
canonical: "https://help.opensense.com/docs/clone-outlook-add-in-domain-settings-with-scenarios-and-best-practices"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.opensense.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Configuring the Outlook Add-in in Domain Settings

## Overview

Domain Settings control how the Opensense Outlook Add-in behaves for users in your organization. This article covers each setting, what it does, and how to configure the right combination for common scenarios, including shared inboxes, alias accounts, and multi-signature deployments.

You configure these settings in the Opensense portal, under **Manage** > **Domain Settings** > **Outlook Add-in**. You need Domain Admin access to manage them.

:::tip[Change not showing?]
After you change a setting, allow a few minutes for it to take effect. If the change doesn't appear right away, clear the add-in cache. See [Step 3 in Troubleshooting the Outlook Add-in](https://help.opensense.com/docs/outlook-add-in-troubleshooting-guide-2#step-3-rename-the-add-in-cache-folders).
:::

## Before you start

You need:

- Domain Admin access in the Opensense portal
- The Opensense Outlook Add-in deployed to your users through Microsoft 365 Integrated apps. See [Scoping Outlook Add-in users in the Microsoft 365 admin center](https://help.opensense.com/docs/clone-outlook-add-in-scope-users-for-opensense-in-m365-admin).

## General settings

![Outlook Add-in General settings in Domain Settings: Automatic Signatures, Default Signature Mode, Multiple Signatures, Plain Text Preview, Disable Default Signature, User Controlled Settings, Visual Preview, Remove Signature for Unknown Domain, Allow Default Override, and Inline Images, each with an Edit link](https://help.opensense.com/media/image1-1c028225764a.jpg)

<div class="kb-deployment-compare kb-deployment-compare--plain kb-deployment-compare--settings">
  <div class="kb-deployment-compare__viewport" role="region" aria-label="Outlook Add-in general settings" tabindex="0">
    <table>
      <colgroup><col class="kb-deployment-compare__feature-col"><col class="kb-deployment-compare__detail-col"></colgroup>
      <thead>
        <tr>
          <th scope="col">Setting</th>
          <th scope="col"><span class="kb-deployment-compare__method">What it does</span></th>
          <th scope="col"><span class="kb-deployment-compare__method">Turn it on for</span></th>
        </tr>
      </thead>
      <tbody>
        <tr class="kb-deployment-compare__band">
          <th scope="rowgroup" colspan="3"><span class="kb-deployment-compare__group">Signature insertion</span></th>
        </tr>
        <tr>
          <th scope="row" id="automatic-signatures">Automatic Signatures</th>
          <td>Inserts the assigned signature automatically each time a user opens a new compose, reply, or forward window. No user action is required.</td>
          <td>Most deployments</td>
        </tr>
        <tr>
          <th scope="row" id="disable-default-signature">Disable Default Signature</th>
          <td>Removes any native Outlook signatures the user has set up. This prevents duplicate signatures when the Opensense signature is also present.</td>
          <td>Most routed and Stamping deployments</td>
        </tr>
        <tr>
          <th scope="row" id="user-controlled-settings">User Controlled Settings</th>
          <td>Shows users two manual toggles in the add-in pane: Disable Default Signature and Insert Automatically.</td>
          <td>Testing, or environments where users need manual control over signature behavior</td>
        </tr>
      </tbody>
      <tbody>
        <tr class="kb-deployment-compare__band">
          <th scope="rowgroup" colspan="3"><span class="kb-deployment-compare__group">Preview mode</span></th>
        </tr>
        <tr>
          <th scope="row" id="plain-text-preview">Plain Text Preview</th>
          <td>Lets the add-in insert the <code>[[#]]</code> token into the compose window for server-side transformation.</td>
          <td>Plain Text Block deployments</td>
        </tr>
        <tr>
          <th scope="row" id="visual-preview">Visual Preview</th>
          <td>Lets the add-in render the full HTML signature in the compose window. If it is off, the visual preview doesn't display, even if the user's signature template is configured for it.</td>
          <td>Visual Preview deployments</td>
        </tr>
        <tr>
          <th scope="row" id="default-signature-mode">Default Signature Mode</th>
          <td>Sets which mode is the default when both Visual Preview and Plain Text Preview are turned on.</td>
          <td>Domains with both preview modes on. Set it to match your primary deployment method.</td>
        </tr>
        <tr>
          <th scope="row" id="allow-default-override">Allow Default Override</th>
          <td>Lets users choose between Plain Text Preview and Visual Preview from the add-in pane. Their choice persists across compose sessions.</td>
          <td>Rarely. This setting isn't commonly used, and mainly matters when both preview modes are on for a domain.</td>
        </tr>
      </tbody>
      <tbody>
        <tr class="kb-deployment-compare__band">
          <th scope="rowgroup" colspan="3"><span class="kb-deployment-compare__group">Multiple signatures</span></th>
        </tr>
        <tr>
          <th scope="row" id="multiple-signatures">Multiple Signatures</th>
          <td>Lets users switch between multiple assigned signatures from the add-in pane. Signature priority and assignment must be configured in Routes. See <a href="https://help.opensense.com/docs/clone-outlook-add-in-multi-signature-selector">Setting up multiple signatures in the Outlook Add-in</a>.</td>
          <td>Users who switch between assigned signatures</td>
        </tr>
        <tr>
          <th scope="row" id="allow-default-override-multiple-signature">Allow Default Override (Multiple Signature)</th>
          <td>Controls what the multi-signature selector shows on each new compose window. Off: users always reset to the priority template. On: users keep their last selected signature across compose sessions.</td>
          <td>Users who should keep their last selected signature</td>
        </tr>
      </tbody>
      <tbody>
        <tr class="kb-deployment-compare__band">
          <th scope="rowgroup" colspan="3"><span class="kb-deployment-compare__group">From address</span></th>
        </tr>
        <tr>
          <th scope="row" id="remove-signature-for-unknown-domain">Remove Signature for Unknown Domain</th>
          <td>Clears the signature if the user switches the From address to a domain that Opensense doesn't recognize. This prevents a stale or incorrect signature when sending from an unrecognized domain.</td>
          <td>Users who switch From addresses. Every domain your organization sends from must be listed under <a href="#internal-domains">Internal Domains</a>, or it won't work correctly.</td>
        </tr>
      </tbody>
    </table>
  </div>
</div>

### Inline Images

Inline images are supported across all Microsoft 365 Outlook clients, including Classic Outlook, New Outlook, Outlook for Mac, OWA, and Outlook Mobile.

To turn on inline images:

1. Turn on **Inline Images** in Domain Settings.
2. Add `?inline=1` to the end of every image URL in the signature HTML. For example: `https://smart.customer.com/v2/imagebucket/customer.com/logo.png?inline=1`

:::caution[Don't use SVG images]
SVG images aren't supported in add-in-deployed signatures. An SVG image in a signature template makes the visual preview insert fail entirely, not just render incorrectly. Use PNG or JPG for all images, including logos and headshots.
:::


## Configuring Internal Domains

The Internal Domains list tells Opensense which domains are part of your organization. From Switching needs it to work correctly when users send from alias addresses or multiple domains. If a user switches to a From address on a domain that isn't in this list, the add-in returns a `400 Unauthorized` error, and no signature appears.

1. In the left navigation, select **Manage**, and then select **Domains**.
2. Select the ellipsis (**...**) on the card of the domain you want to configure, and then select **Manage Domain**.
3. In the left navigation, select **Domain Settings**. Under **General**, find the **Internal Domains** field, and select **Edit**.
4. Add each alias or sending domain your users send from, and then select **Save**.
5. If your organization has multiple primary domains, repeat these steps for each one, adding the other primary domains to each domain's Internal Domains list.

![Domain Settings, General, Domains section: White Label Domain, Domain Aliases, and Internal Domains, each with an Edit link](https://help.opensense.com/media/image2-2-909b50b72b1e.jpg)

:::caution[Clearing the cache won't fix a 400 error]
Clearing the add-in cache doesn't resolve a `400 Unauthorized` error when switching From addresses. The fix is always to add the domain to the Internal Domains list. If your organization has several primary sending domains and needs this update on all of them, contact [help@opensense.com](mailto:help@opensense.com) for help.
:::

## User and signature fields

![User and Signature Fields in Domain Settings: Dynamic Fields off, Editable Fields, Signature Fields Only, and Custom Compose Fields on, and a Custom Compose Fields Configuration with five checkboxes](https://help.opensense.com/media/image3-8a14296f9f6e.jpg)

<dl class="kb-insights-summary">
  <div><dt id="dynamic-fields">Dynamic Fields</dt><dd>Signature fields can adjust in real time based on the recipient, for full Visual Preview deployments. See the caution below before you turn this on.</dd></div>
  <div><dt id="editable-fields">Editable Fields</dt><dd>Users can change select fields in their signature from the add-in pane. Only fields <strong>unlocked</strong> in the signature template are editable. Fields with a lock icon are admin-controlled, and users can't edit them, whatever this setting is.</dd></div>
  <div><dt id="signature-fields-only">Signature Fields Only</dt><dd>The add-in pane shows only the fields in the user's assigned signature template. Fields in the user's Opensense profile but not in their template are hidden. This keeps the add-in pane focused, and prevents confusion when templates use a subset of the available profile data.</dd></div>
  <div><dt id="custom-compose-fields">Custom Compose Fields</dt><dd>Extra fields appear in the add-in pane, for users to toggle or fill in before sending. You configure them under <strong>Custom Compose Fields Configuration</strong>, and use them to control optional signature elements, such as pronouns, phone visibility, or meeting links. For setup detail, see <a href="https://help.opensense.com/docs/custom-compose-fields">Setting up Custom Compose Fields for the Outlook Add-in</a>.</dd></div>
</dl>

:::caution[Dynamic Fields limitations]
Dynamic Fields conflicts with the HubSpot Sales add-in. It also applies only to the last recipient added to the **To** field, not to all recipients. Avoid this setting unless no other option is available for your configuration.
:::

## Email tracking

### Activity Feed

When this is on, an **Activity** tab in the add-in pane shows the user engagement data for their sent emails, including opens and link clicks. This setting requires a compatible Opensense engagement tier. To confirm whether your plan includes it, contact [help@opensense.com](mailto:help@opensense.com) or your account manager. Learn more about [Opensense email tracking and analytics](https://www.opensense.com/email-tracking-and-analytics).

## Aliases and shared inboxes

Three settings control the signature when a user switches the From address: **From Switching**, **Merge User Fields**, and **Ignore Empty Fields**. The combination you choose depends on whether the signature should reflect the primary user's identity or the switched account's identity.

![Aliases and Shared Inboxes in Domain Settings, with From Switching, Merge User Fields, and Ignore Empty Fields all turned on](https://help.opensense.com/media/image4-3fe8cfa4b2ed.jpg)

<div class="kb-deployment-compare kb-deployment-compare--plain">
  <div class="kb-deployment-compare__viewport" role="region" aria-label="From Switching configurations compared" tabindex="0">
    <table>
      <colgroup><col class="kb-deployment-compare__feature-col"></colgroup>
      <thead>
        <tr>
          <th scope="col">Configuration</th>
          <th scope="col"><span class="kb-deployment-compare__method">Signature shows</span></th>
          <th scope="col"><span class="kb-deployment-compare__method">Scenario</span></th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <th scope="row"><a href="#from-switching-off">From Switching off</a></th>
          <td>The primary user's information, whichever From address is selected</td>
          <td>The primary user's information should always appear when sending from a shared inbox.</td>
        </tr>
        <tr>
          <th scope="row"><a href="#from-switching-on">From Switching on</a></th>
          <td>The selected account's data. The primary user's data isn't used.</td>
          <td>A shared inbox like <code>support@company.com</code> should show its own signature data, not the sending user's personal details.</td>
        </tr>
        <tr>
          <th scope="row"><a href="#from-switching-on-with-merged-fields">From Switching on, with merged fields</a></th>
          <td>The selected account's data, with the primary user's information filling any missing or empty fields</td>
          <td>A shared inbox like <code>help@company.com</code> should show the sending user's name and title, but always the shared inbox's email address.</td>
        </tr>
      </tbody>
    </table>
  </div>
</div>

:::note[Not the Outlook Mobile limitation]
These settings are unrelated to the Outlook Mobile account-switching limitation described in the [Outlook Add-in overview](https://help.opensense.com/docs/outlook-add-in-overview-1#outlook-mobile-from-switching-limitation). That limitation is a Microsoft platform constraint on mobile devices, and you can't change it in Domain Settings.
:::

### From Switching off

The signature always shows the primary user's information, whichever From address is selected. This is the simplest configuration, and the right choice when employees should send from all accounts with their own personal signature.

For Plain Text Block deployments, the fields on the other account must be unlocked, so the primary user's data can populate them. For Visual Preview deployments, the primary user's data appears whatever the field lock state, because the signature is inserted client-side.

### From Switching on

When a user switches the From address, the signature template updates to show the data of the selected account. The primary user's data isn't used. Use this setting when shared or alias accounts have their own distinct signature requirements.


### From Switching on, with merged fields

Turn on **From Switching**, **Merge User Fields**, and **Ignore Empty Fields**. This is the recommended configuration when you want data to merge from the primary user into alias or shared account signatures. When a user switches to an account with missing or empty fields, the primary user's information fills those fields.

For merging to work correctly, the fields you want merged must either not exist on the switched account, or have their values cleared. If a field has data on the alias account, Merge User Fields doesn't overwrite it. That's why Ignore Empty Fields should always be on alongside Merge User Fields: it makes sure the primary user's data fills only the fields that are genuinely empty, not fields that already have values.

For a shared inbox whose signature should show the primary user's name and title, but keep the shared inbox's own email address and other data:

1. Unlock the fields you want merged on the shared account (for example, name and title).
2. Break the directory sync on those fields, so they accept the merged values instead of pulling from the shared account's directory data. See [How should I break the directory sync in Opensense?](https://help.opensense.com/docs/breaking-directory-sync-in-opensense)
3. Clear the existing values of the fields that should pull from the primary user.
4. Keep the fields that should keep the shared account's own values locked, with the correct data in place.


## What's next

- [Outlook Add-in overview](https://help.opensense.com/docs/outlook-add-in-overview-1)
- [Setting up multiple signatures in the Outlook Add-in](https://help.opensense.com/docs/clone-outlook-add-in-multi-signature-selector)
- [Expected behaviors in routed Outlook Add-in deployments](https://help.opensense.com/docs/clone-outlook-add-in-routed-key-behaviors-and-nuances)
- [Troubleshooting the Outlook Add-in](https://help.opensense.com/docs/outlook-add-in-troubleshooting-guide-2)