4.3. Centralized deployment (Microsoft 365)

Centralized deployment through the Microsoft 365 admin center is the recommended distribution channel for a corporate rollout. The operator uploads site/manifest.xml once, assigns the add-in to users or groups, and Outlook (both desktop and web) picks it up on the next sync.

4.3.1. Prerequisites

  • A Microsoft 365 admin with the Global Administrator or Exchange Administrator role.

  • The target users have mailboxes hosted on Exchange Online (centralized deployment does not cover purely on-prem Exchange).

  • The task pane bundle is already published on the customer’s HTTPS origin (see Hosting the task pane), and manifest.xml has been rewritten by apply-host with that hostname.

4.3.2. Upload procedure

  1. Open https://admin.microsoft.com .

  2. Navigate to Settings -> Integrated apps.

  3. Click Upload custom apps.

  4. Select Office Add-in as the app type, then Upload manifest file (.xml) from device and pick site/manifest.xml.

  5. On the Users step choose Entire organization, Specific users/groups, or Just me for a smoke test.

  6. Review and Deploy. Microsoft caches the manifest on their side; allow up to a few hours for it to reach all clients on the first rollout.

4.3.3. Verifying the deployment

Open any received email in Outlook (desktop, web, or new Outlook). The button labelled Archivovat email should appear on the Message ribbon (desktop) or in the ellipsis menu (web, depending on the ribbon customisation). Clicking it opens the task pane, which in turn fetches the domain list from the server via /api/ on the same origin.

If the button does not appear:

  • Wait longer - first-time propagation can take up to 24 hours.

  • In Outlook on the web: Settings -> Mail -> Customize actions and confirm the action is enabled.

  • Check the admin center’s Integrated apps page for a deployment error (typically caused by an unreachable manifest URL or an invalid certificate on the hosting origin).

4.3.4. Updating an already deployed add-in

  1. Increment <Version> in the new manifest (the release build does this automatically).

  2. Rebuild the client bundle and rewrite the hostname with apply-host the same way as for a fresh install.

  3. Replace the contents of the hosting origin’s site/ folder.

  4. In the admin center, open the app under Integrated apps, click Update and upload the new manifest.xml.

  5. Outlook clients pull the new manifest on their next check - usually within a few hours, at the latest on the next sign-in.

Do not change <Id> between versions unless the requested <Permissions> level has changed. Rotating the GUID forces Outlook to treat the update as a brand-new add-in and every user has to re-accept the permission prompt.

4.3.5. Removing the add-in

In Integrated apps, select the add-in and choose Remove. The button disappears from Outlook on the next manifest refresh; the static bundle on the hosting origin and the server-side import data are not affected - take them down separately.