Forum Discussion
How to Find Active EWS-Based Apps in a Microsoft 365 Tenant
Microsoft will retire Exchange Web Services (EWS) from Exchange Online on October 1, 2026. A new usage report helps tenants understand what apps use EWS. Many of the apps are likely to be first-party (Microsoft) apps, but some might be third-party apps developed externally or internally. Those apps need to be retired or upgraded to use Graph APIs. Time is slipping away to do the work.
https://office365itpros.com/2025/04/29/exchange-web-services-apps/
12 Replies
Hi TonyRedmond
One thing I have noticed is inconstancy in the Report,
I Ran it 3 Days ago and it found nothing in the last 7 Days, then Ran it again today and it found 10 Applications Using EWS on a Date that was within the Range of the 7 Days of the First Run of the Report. I am wondering if the data from this report can be relied upon?
Kind Regards,
Steve
Well, it's the only data that we have to go on, and I assume that someone at Microsoft is checking the information and even tweaking the report to improve the quality and accuracy of the data (I will ask).
If you are struggling to find the App IDs it is easier in PowerShell using the following
#Get Azure App Name from App ID
Connect-MgGraph -Scopes Application.Read.All
$appid = Read-Host "Enter App ID"
Get-MgServicePrincipal -Filter "Appid eq '$appid'"To find active EWS-based apps in your Microsoft 365 tenant, go to the Microsoft 365 admin center and check the new EWS Usage Report. This report shows which apps are still using EWS, so you can identify any third-party or custom apps that need to be updated or replaced before Microsoft retires EWS on October 1, 2026. Start reviewing now—time flies!
Hi Matt-Apps4Rent,
Thanks for replying. I have found the report in the admin center, but that is showing only the ID's, not the names. And not all ID's are found back in Entra. TonyRedmond explained that these are Microsoft apps, so I don't need to worry about that.
Kind regards,
Arjan
Try searching Google or Bing to find any references to the GUID you see. If you can’t find anything, the app is likely an internal Microsoft app.
Hi TonyRedmond
Thanks for replying. I have searched the GUID's with Google, but no results show up. So these would be internal Microsoft apps.
Some Microsoft apps are still using EWS (for example Microsoft Teams, Microsoft Outlook or Office 365 Exchange Online are on the EWS Usage report). Do we have to take action for these apps? Or can we ignore them and will Microsoft change these apps so these will not use EWS anymore?
Kind regards,
ArjanMicrosoft will take care of its own apps by October 2024. The ones you've got to worry about are those from ISVs or internally-developed apps.
Hi TonyRedmond
Thanks for this usefull information! I used the information you placed on your website to identity apps that still using EWS. But some of the apps mentioned in the usage report are not show up when I search them by ID. Is there a possibility to identity these apps another way?
Kind regards,
Arjan
