406 Not Acceptable may be returned when sending a web push notification to Microsoft Edge based on RFC 8292

Question

406 Not Acceptable may be returned when sending a web push notification to Microsoft Edge based on RFC 8292.
I would like information on this event.

We are trying to send a web push to various browsers.
For Microsoft Edge as well, we calculate the VAPID, set the Authorization to that value, and send the request to the endpoint https://*.notify.windows.com/w/?token=* .

If we send push notifications to many users, sometimes we receive '406 Not Acceptable' as responses.
If we receive this error, we can not send the message properly for about an hour to a day afterwards.
We understand that the '406 Not Acceptable' is due to throttling on Microsoft's part triggered by sending too many push notification requests in certain amount of time, but we are having trouble finding documentation on how much to send to be limited.

We would like information on the following points

• The approximate rate of transmission and throttling that will not overload the service.
• Can these limitations be relaxed by pre-authorizing the service, like push notifications to UWP applications?
• Whether there is any technical text on these.

Thank you.

Answer 1

Hi @takada ,

Yes, you are right. The error 406 Not Acceptable will be provided given if send excessive notifications. As described in the official documentation about this error message:

As far as I know， there is no specifications from Microsoft about the policies applied for intervals or numbers, precisely to prevent circumventing or exploiting this policies by setting just the right amount of time to avoid the policy. And I also didn't find a policy that fits your needs in the Edge group policy documentation, so I'm afraid there is no such service to relax this restriction.

Best regards,
Xudong Peng

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Answer 2

Hi @XuDong Peng-MSFT Can you share a link to the documentation you're referencing? We're also facing this issue and we're not certain whether the rate limit applies to requests from a single IP, pushes to a given browser, or something else.

Answer 3

Hi, i also have the same problem.

Answer 4

I just send literally 8 notification, and get this error, since yesterday. Why? Is that a lot of notifications? I send around 10 per hour..