Legacy Feature | Availability in Web Add-in | Reason for Removal |
|---|---|---|
Automatic categorisation of saved e-mails (“Saved” purple category) |
Not supported
Supported in clients supporting Mailbox API v1.8+, list of supported clients - https://learn.microsoft.com/en-us/javascript/api/requirement-sets/outlook/outlook-api-requirement-sets?view=common-js-preview&tabs=jsonmanifest#outlook-client-support | ||
Real-time monitoring of incoming e-mails (background operation) | Not supported | Modern add-ins execute only when the task-pane is open; global “all-items” events aren’t exposed. |
Processing while Outlook is minimised (VSTO background thread) | Not supported | Office JS code stops once the pane closes; persistent background threads are disallowed. |
Automatic display / persistent pinning of the add-in pane | Partially supported — user must open the pane; *Pin* works only in Windows desktop Outlook, not in Outlook on the web | Office JS cannot programmatically open or pin the pane; OWA currently lacks a pinning feature. |
MSI installer / GPO push deployment | Replaced — install via Microsoft 365 admin center |
→ Settings → Integrated Apps or per-user sideloading | Modern add-ins are manifest-based web apps; Microsoft has deprecated MSI + |
GPO deployment for Outlook add-ins. | ||
Bulk / silent configuration for multiple users (registry or script) | Not supported | Office JS settings are stored per mailbox and must be set interactively; no bulk-write API is available yet. |
Registry-based silent configuration | Replaced with interactive |
Settings UI | Web add-ins cannot read Windows Registry; settings must live in roaming storage. | |
Direct opening of cases in Patricia Desktop | Not supported | Office JS cannot access local desktop apps. |
Support for Outlook 2007 / 2010 / 2013 | Dropped | Microsoft allows modern add-ins only on Outlook 2016 (build 16.0.9126) and newer. |
Direct COM access to Outlook object model | Not supported | COM interop is unavailable in Office JS; only the subset exposed by Office JS can be used. |
Local log file `DocIntegrateOutlook.log` | Replaced with in-pane diagnostics | Browser sandbox prevents writing to the local file system; diagnostics surface inside the pane. |
Support for non-HTTPS DMS endpoints | Dropped — HTTPS required | Office JS blocks insecure HTTP requests inside Outlook; mixed content is disallowed. |
What this means for users
- The add-in pane is not shown automatically. In In specific versions of Outlook for Windows you can open it once and press *Pin* to keep it docked; in Outlook on the web and new versions of Outlook you must open it manually every time.No more “Saved” colour labels in the mailbox list. Open the message and check the add-in pane for DMS status.
- The add-in processes e-mails only while its pane is open. Switch Switch away and processing pauses.
- Installation for multiple users is done goes through the *Microsoft 365 admin center → Integrated Apps* (or each user can install individually); Group Policy MSI + GPO deployment is no longer supported.
- Each user must configure their own DMS connection (gear-icon *Settings*); bulk pre-loading is not available today.
- Opening of cases in Patricia Desktop is not supported anymore
- The DMS URL must start with https:// — plain http:// endpoints are rejected.
- Outlook ≤ 2013 is no longer supported. Those Those users should stay on the legacy add-in or upgrade Outlook.
...
- Security — modern add-ins run in a sandbox: no COM, Registry, file-system access, or insecure HTTP traffic.
- Governance — Microsoft has deprecated MSI / GPO add-in deployment; admin-center installation and manifest sideloading are the supported paths.
- Cross-platform — one code-base for Windows, Mac, Web, and Mobile required dropping Windows-only hooks and MSI installersdirect desktop launches.
We will continue to watch the Office JS and Microsoft Graph roadmaps and re-introduce any of the above features if the necessary APIs become available.