Monitoring many mailboxes in Exchange OnLine RRS feed

  • Question

  • Hi

    I'm developing a large-scaled Exchange calendar synchronization application using EWS Managed API 2.1. 

    When Microsoft upgraded the Exchange OnLine platform to Exchange 2013 I had to re-write some of the code in order to adapt to the new behavior of the CAS (e.g. subscription groups and GroupingInformation).

    Typically our customers have 4000-5000 mailboxes that we have to monitor but some of them have 20.0000 or more. As the trend is that also large companies are moving their Exchange to the cloud I often get questions from sales about how many calendars we can monitor for changes.   

    So, now to my question;

    Is there any absolute limit for how many mailboxes that can be monitored in Exchange OnLine?

    I'm using EWS Managed API 2.1, utilizing Autodiscover, Impersonation, Streaming Notifications and subscription groups (200 subscriptions each). I'm aware of that throttling limits will be reached from time to time and that I have to handle them as they occur.

    Best Regards


    Jens Eriksson TalkIT Communication AB

    Wednesday, October 22, 2014 9:36 AM