If you rely on Zoom, Cisco Webex, or another third-party meeting provider, you may have noticed that the default online meeting button behaves differently in the new Outlook for Windows. In classic Outlook, third-party add-ins like the Zoom for Outlook add-in could set themselves as the default online meeting provider. The new Outlook replaces this system with a centralized provider model that only supports Microsoft Teams and Skype for Business by default. This article explains what changed in the provider architecture, how to restore third-party meeting defaults, and what limitations remain in the new Outlook.
Key Takeaways: Third-Party Meeting Defaults in New Outlook
- New Outlook provider model: Only Microsoft Teams and Skype for Business are built-in; third-party add-ins cannot set themselves as the default online meeting provider.
- Third-party add-in installation: Providers like Zoom and Cisco Webex must install a specific new Outlook-compatible add-in from AppSource to enable the Online Meeting button.
- Default provider override: If a third-party add-in is installed, the new Outlook uses the last-used provider as the default, but classic Outlook allowed permanent default assignment via add-in settings.
How the Online Meeting Provider System Changed
In classic Outlook, third-party meeting providers used COM add-ins that registered themselves as the default online meeting tool. When you installed the Zoom for Outlook add-in, for example, it added a Zoom Meeting button to the ribbon and set itself as the default provider for new meeting requests. The classic Outlook architecture allowed these add-ins to intercept the Online Meeting button and replace the built-in Teams or Skype option.
The new Outlook for Windows uses a completely different add-in platform based on web technologies (Office Add-ins framework). This platform does not allow third-party add-ins to override the default online meeting provider at the system level. Instead, each add-in must register as a meeting provider through the Microsoft 365 AppSource store. The new Outlook then lists all installed providers in a dropdown menu next to the Online Meeting button. The user must select the provider manually for each meeting or rely on the last-used provider as the default.
This change affects all third-party meeting providers that worked in classic Outlook. Microsoft Teams and Skype for Business remain as built-in providers that are always available. No third-party add-in can replace them as the permanent default provider in the new Outlook.
Steps to Set a Third-Party Meeting Provider as Default in New Outlook
Follow these steps to install a third-party meeting add-in and set it as your default online meeting provider in the new Outlook for Windows.
- Open the new Outlook and go to Get Add-ins
Click the Get Add-ins button on the Home tab of the ribbon. Alternatively, select File > Manage Add-ins to open the Add-ins management page in your browser. - Search for your meeting provider add-in
In the AppSource store, search for your provider name such as Zoom for Outlook or Cisco Webex for Outlook. Only add-ins labeled as compatible with new Outlook will appear. Classic COM add-ins will not show up. - Install the add-in
Click Add next to the add-in. Review the permissions and click Continue. The add-in will be installed and appear in the ribbon under the Home tab. - Create a new meeting and select the provider
Click New Meeting on the Home tab. In the meeting form, click the Online Meeting button. A dropdown menu shows all installed providers. Select your third-party provider. The meeting details will include the provider’s join link and meeting ID. - Set the provider as default for future meetings
The new Outlook remembers your last-used provider. After you select a third-party provider once, the Online Meeting button will default to that provider for subsequent meetings. To change it again, repeat step 4 and select a different provider. There is no permanent default setting; the system uses the last choice.
Limitations and Workarounds for Third-Party Meeting Defaults
The new Outlook introduces several limitations that affect how third-party meeting providers behave. Understanding these will help you decide whether to switch to the new Outlook or keep using classic Outlook.
No permanent default provider assignment
Classic Outlook allowed you to set a third-party provider as the default through the add-in’s own settings dialog. The new Outlook does not expose this option. The only way to control the default is by selecting a provider from the dropdown menu each time you create a meeting. The last-used provider becomes the default until you select a different one.
Provider add-in must be from AppSource
Only add-ins published through the Microsoft 365 AppSource store work in the new Outlook. If your organization uses a custom or legacy third-party meeting add-in, it will not appear in the new Outlook. The provider must publish a new Outlook-compatible version. Zoom and Cisco Webex have released compatible add-ins. Check your provider’s documentation for availability.
Meeting provider features may differ
Some third-party meeting features available in classic Outlook may not work in the new Outlook. For example, automatic insertion of meeting passwords or custom branding may be missing. The add-in developer controls which features are exposed in the new Outlook framework. Test all meeting workflows before switching.
Switch back to classic Outlook if needed
If the limitations prevent your team from using third-party meeting defaults, you can switch back to classic Outlook. In the new Outlook, click the toggle switch at the top-right corner labeled Try the new Outlook. Slide it to the Off position. Outlook will reopen in classic mode with all COM add-ins restored.
New Outlook vs Classic Outlook: Third-Party Meeting Provider Comparison
| Item | New Outlook | Classic Outlook |
|---|---|---|
| Default provider model | Last-used provider from dropdown | Permanent default set by add-in settings |
| Third-party add-in type | Web-based Office Add-in from AppSource | COM add-in installed locally |
| Provider override | Cannot override built-in Teams/Skype | Can replace default with third-party |
| Ribbon button behavior | Dropdown menu lists all providers | Single button from the default provider |
| Feature parity | Limited to add-in developer implementation | Full access to add-in features |
If the Third-Party Meeting Button Does Not Appear
If you installed a compatible add-in but the Online Meeting button does not show your third-party provider, check the following.
Add-in is not enabled
Go to File > Manage Add-ins. Verify the add-in is listed and toggled On. If it is Off, turn it On and restart Outlook.
Add-in is not compatible with your Outlook version
Some add-ins require the latest version of new Outlook. Go to File > Office Account > Update Options > Update Now to install the latest updates. After updating, check the add-in again.
Provider requires a separate desktop app
Zoom and Cisco Webex add-ins require the desktop client to be installed on your computer. If the client is missing, the add-in will not generate meeting links. Install the provider’s desktop app and restart Outlook.
Organizational policy blocks the add-in
Your IT administrator may block third-party add-ins through Microsoft 365 admin center policies. Contact your IT department to request access to the specific add-in.
The new Outlook replaces the classic COM add-in system with a web-based add-in model that limits third-party meeting provider defaults. You can install compatible add-ins from AppSource and use the last-provider selection as a workaround. If your workflow requires a permanent default third-party provider, stay with classic Outlook until Microsoft adds this capability to the new Outlook. Test the last-provider behavior with a few meetings before making the switch for your entire team.