O365 Webhook Subscriptions for All Users Calendars

Question

There is an existing question which already has an answer; however, the answer comes from a Microsoft developer and reads, "We are working to support the scenario you are requesting..." and goes on to provide a method which doesn't seem to answer my question.

Original article: Using Microsoft graph to read all users calendars

My question is, rather than subscribing to a single user's mailbox or calendar, is it possible to subscribe to all mailboxes or calendars?

My application needs to listen to the create/update/delete events of calendar meetings and insert them into a SharePoint list.

POST https://graph.microsoft.com/v1.0/subscriptions
Content-type: application/json

{
   "changeType": "created,updated",
   "notificationUrl": "https://webhook.azurewebsites.net/api/send/myNotifyClient",
   "resource": "me/mailFolders('Inbox')/messages",
   "expirationDateTime":"2016-11-20T18:23:45.9356913Z",
   "clientState": "subscription-identifier"
}

References:

1. Using Microsoft graph to read all users calendars

2. Creating a subscription - https://developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/api/subscription_post_subscriptions

Hellion

Have you found a solution for this? My current thoughts is that it is not possible, further more the subscription limits seem to make webhooks only usable on a very small scale – Kelp

Not exactly - rather, I am just creating individual subscriptions on every user in AD. The subscriptions will expire, so I save the date and time of the subscription (storing the subscription in the database is required for validation anyway) and I use it to renew the subscription via the API. – Hellion

How many users do you have? I would be fine with creating individual subscriptions, but I hit the limits described on this page : developer.microsoft.com/en-us/graph/docs/api-reference/v1.0/… which is 7 on the same app / tenant; after that further subscription requests fail. – Kelp

We intended this to work with a large number of users but development has actually stopped prior to larger scale testing. I was not aware of the limitations you referenced. Why would they do that!? I don't quite understand it; an "app" supports 50k subscriptions, but the same "app" on a "tenant" only supports 7 subscriptions? How would the be useful whatsoever? – Hellion

I find it very strange, especially as webhooks feel like a more advanced / enterprise feature. I have opened another question in the hopes of getting to the bottom of it, for your book marking convenience : #50276493 : ) – Kelp

If all else fails, I work for a Microsoft Gold Partner so I will see about scheduling a call with Microsoft to learn more about these limitations. I'll post back here if I find anything. – Hellion

Answer 1

This feature is not available today. If you'd like to request this feature you can create an idea on uservoice

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