One of the great benefits to running one of the world’s largest Exchange deployments is that we at Microsoft get to see all the things that our customers face on a daily basis. With the recent release of iOS6, we have noticed a marked increase in support calls due to meetings having the owner of the meeting changed (sometimes called “meeting hijacking”). Most instances reported to us to date involve users with delegates who first open a meeting request in Outlook and then act on that same meeting in iOS.

Meeting issues are a large part of the challenges that we know some organizations see with 3rd party devices (here is our list). Unfortunately the recent iOS update has exacerbated one of these issues. We wanted to let you know about this issue as well as let you know that we have discussed this issue with Apple. We are also looking at ways that we can continue to harden the Exchange infrastructure to protect our servers and service from poorly performing clients.

In the meantime we wanted to offer a few mitigation options:

  • Tell users not to take action on calendars on iOS We're not seeing this particular issue if users don't take action on their calendar items (for example, accept, delete or change meetings).

  • Switch iOS users to POP3/IMAP4 Another option is to switch users over to POP/IMAP connections. This will remove calendar and contacts functionality while allowing users to still use email (though the email may shift to pull from push while using these protocols).

  • 3rd party clients/OWA Moving impacted users over to another email client that is not causing these issue for your organization may help alleviate the pain here. There are a number of other client options (OWA being one of them of course). Numerous clients are available in mobile application stores. We don’t recommend any particular client.

  • Block delegates Many of the issues we are seeing involve delegates. An admin can take the less drastic step of using the Allow/Block/Quarantine list to block only users who are delegates, or have a delegate, to minimize the impact here.

  • Block iOS 6 devices Exchange server comes with the Allow/Block/Quarantine functionality that enables admins to block any device or user.

  • Tell users not to upgrade to iOS 6 or to downgrade their devices – This solution may work as a temporary fix until Apple provides a fix but many users may have already made the decision to update.

  • Wait We do not have any information on the timeline of a fix from Apple but if this timeline is short, this may be the easiest course of action. Please contact Apple about any potential fix or timeline for its delivery.

  • Our support team has also published a KB article on this issue that you can read here. And we will update this post when a fix is available or we have additional information.

  • Adam Glick
    Sr. Technical Product Manager