Migrate from COM add-ins to web add-ins

In the new Outlook for Windows, web add-ins are fully supported, with no other work required from partners. COM add-ins aren't supported in the new Outlook for Windows, but continue to work in classic Outlook for Windows. COM add-ins can manipulate Outlook in many ways that often leads to instability and crashes in Outlook. To ensure Outlook is more stable and robust, web add-ins provide a sandbox environment for add-ins to operate in and have checks and balances in place.

COM add-ins differ from web add-ins in several ways; one example is the use of fixed entry points. Using fixed entry points is intentional to ensure a stable and consistent experience for all Outlook users.

Note

Classic Outlook supports web add-ins and continues to get the latest web add-in features. To learn more, see Office Add-ins platform overview.

The web add-ins platform in Outlook is advancing, with significant updates for both new Outlook and classic Outlook on Windows. These updates bring a host of modern capabilities and integrated experiences, ensuring that:

• Add-ins run automatically during event changes without disrupting the workflow.
• Users can apply add-ins to multiple items with ease.
• Items are validated and corrected as necessary before sending.
• Phishing reports are more effective, supported by contextual tips.
• Mail or event details are updated seamlessly.

Transitioning add-ins from classic Outlook to the new Outlook for Windows

If your organization is currently using web add-ins, no extra effort is required to use it in the new Outlook. If your organization is using a COM add-in, there are a few steps you can take to transition to web add-ins:

1. Check your installed COM add-ins: You can check installed COM/VSTO add-ins from the Microsoft 365 Apps health dashboard in the Microsoft 365 Apps admin center. To find your installed apps, follow the instructions in Add-in health—and be sure to filter out only the Outlook add-ins.

2. Identify the mission-critical COM add-ins from this list: Often, organizations have unused COM add-ins installed that are no longer relevant. It's important to identify and prioritize the COM add-ins that are actively used by your organization in preparation for the new Outlook for Windows. To identify the relevant COM add-ins, collaborate with your relevant business groups or IT teams.

   Some Microsoft COM add-ins might be deployed within your organization. The plan for these COM add-ins is detailed in Identify COM add-ins in your organization.

3. Check if web add-ins are available for use: If a web add-in is available, install, test, and assess it for usage with the new Outlook for Windows. You can follow the steps in Deploy and manage Office Add-ins to install a web add-in.

   • Some widely used COM add-in publishers also published their web add-ins. The ones marked PRIVATE don't have a web add-in published to the store but have a private web add-in; you can reach out to the partners for requesting access to it.

     COM Add-in	Scenario	Web add-in
     Adobe Acrobat Sign	Signature Management	Adobe Acrobat Sign for Microsoft Outlook
     Barracuda Archive Search for Outlook	Attachment Management	Barracuda Essentials for Outlook
     Blue jeans Outlook Add-in	Online Meetings	BlueJeans Meetings
     Calendly for Outlook	Meeting Boosters	Calendly for Outlook
     Cisco Webex Meetings	Online Meetings	Cisco Webex Scheduler
     Citrix Files for Outlook	Attachment Management	ShareFile
     Cofense Reporter	Phishing/Spam Reporting	PRIVATE- Cofense
     Egress	Encryption & Classification	Egress Protect
     Evernote.Outlook	Productivity	Evernote
     Google Meet Outlook Add-in	Online Meetings	Google Meet Add-In
     GoToMeeting Outlook COM Add-in	Online Meetings	GoTo for Outlook
     harmon.ie	Attachment Management	harmon.ie web add-in
     Jira	Project Management	Jira Cloud
     Mimecast for Outlook	Phishing/Spam Reporting	Mimecast Essentials for Outlook
     OnePlaceMail	Attachment Management	OnePlaceMail for Outlook
     KnowBe4 PhishAlarm Outlook Add-In	Phishing/Spam Reporting	PRIVATE-KnowBe4
     Proofpoint Outlook Plug-in	Phishing/Spam Reporting	PRIVATE-Proofpoint
     Proofpoint Plug-in	Phishing/Spam Reporting	PRIVATE-Proofpoint
     RingCentral Meetings Outlook Plugin	Online Meetings	RingCentral Scheduler
     Salesforce for Outlook	CRM	Salesforce
     Symantec Endpoint Protection Outlook Add in	DLP	PRIVATE-Symantec
     Vera AddIn for Outlook	DLP	Private Vera
     Virtru For Outlook	DLP	PRIVATE-Virtru
     Zoom Outlook Plugin	Online Meetings	Zoom for Outlook Extension

   • If you don't find your relevant COM add-ins on this list, search for them in the Microsoft commercial marketplace.

     Tip

     By default, users are given the option to install web add-in counterparts of their existing COM add-ins when they switch to new Outlook for Windows. For more information, see Install web add-in counterparts of existing COM add-ins in new Outlook for Windows. To learn how to prevent web add-in counterparts from being installed when a user switches to new Outlook for Windows, see Prevent add-ins from being installed during setup.

   • Some developers build private web add-ins that aren't published to the store. Check with your partners to confirm if they developed or are developing a web add-in.

4. Explore native Outlook capabilities. If your mission critical COM add-ins don't have an equivalent web add-in, explore new Outlook's native capabilities and see if they work for your scenario. Some examples include:

   COM Add-in	Native Outlook capability
   Online Meeting	Teams meetings in Outlook
   Security: DLP, Phishing & Spam	Microsoft Purview Information Protection (sensitivity labels, permissions) and Report Message
   Email proofing	Microsoft Editor
   Signature	Outlook Signatures

5. Initiate web add-in development. If native Outlook capabilities don't meet your needs, reach out to your partners or internal developer teams (if there are internally developed COM add-ins) to initiate web add-in development. Here are some resources you can share with your partners or developers to start building web add-ins.

   • Develop Outlook add-ins for the new Outlook for Windows: This document has details on the supported and unsupported COM add-in scenarios in the web add-ins platform.
   • Build your first Outlook add-in
   • Tutorial: Build a message compose Outlook add-in
   • Outlook add-in APIs

   In addition to the JS APIs supported by the web add-in platform, developers can also use Graph API integrations to augment the add-in capabilities.

Request improvements in the web add-in platform

Our goal is to provide support for core scenarios through a combination of Add-in JS and Graph APIs. You can:

• Launch an add-in automatically when sending mail or during an event change.
• Select multiple items at once for the add-in to run on.
• Update mail or writing to the add-in product's server.

For a full list of scenarios, see Supported scenarios in Outlook web add-ins.

If you find gaps in the web add-in platform that don't support core workflows like the COM add-in, use this form to share feedback.

Web add-in FAQs

1. What are the capabilities supported by web add-ins?: Outlook web add-ins support many scenarios involving composing and reading emails and events. Web add-in JS APIs support accessing many properties like the email body and details, event body and details, sensitivity labels and many more. It is also possible to launch web add-ins automatically on email compose and many more capabilities are being added to the web add-in platform. Learn more about the supported and upcoming scenarios in Supported scenarios in Outlook web add-ins.

2. What are the JS API requirements sets supported in new Outlook?: Web add-in JS API set upto 1.14 is supported in the new Outlook for Windows. This provides support for spam reporting and phisihing scenarios among several others. Learn more about the JS APIs in this requirement set here: Outlook API reference.

3. How can spam reporting web add-ins replace the 'Report' button in new Outlook?: Third-party spam reporting add-ins can replace the Report button in new Outlook by making a manifest change. It requires the web add-in manifest to set xsi:type attribute of the ExtensionPoint element to ReportPhishingCommandSurface. More details on the implementation here: Implement an integrated spam-reporting add-in.