Microsoft on Tuesday explained a fix that has been affecting Microsoft Exchange Server 2010 Client Access and Mailbox users on iOS 6. The company explained that, for some reason, users are getting mail retrieval errors and a "connection to the server failed" notification.

Microsoft said that it's working with Apple to figure out a long term solution, but in the meantime Microsoft says users should not "not process Calendar items such as meeting requests on iOS 6.1 devices," and that anyone experiencing the issue should immediately restart the iOS 6.1 device.

If those steps fail, Microsoft suggests trying one or all of the following:

Method 1: Remove and re-create the device partnership

To do this, follow these steps:

  1. On the iOS 6 device, instruct the user to remove the Exchange account.
  2. On a system that is running the Exchange Management Shell, the Exchange Server administrator can run the Remove-ActiveSyncDevice cmdlet to remove the device on the server-side. See the Remove-ActiveSyncDevice topic in Microsoft TechNet online.
  3. Wait 30 minutes, and then instruct the user to add the Exchange account to the device. Advise users not to process Calendar items on the device.
Method 2: Create a custom throttling policy for iOS 6.1 users

To do this, follow these steps:

  1. The Exchange Server administrator can use Log Parser Studio to identify iOS 6.1 users in the organization. For more information, see the Log Parser Studio details in the "More Information section.
  2. Create a custom throttling policy to apply to the iOS 6.1 users. For more information about how to create and apply a custom throttling policy, see the New-ThrottlingPolicy topic in TechNet online.Apply the following values by using a range of 10 to 30, based on organizational needs and testing:
    • EASPercentTimeInCAS
    • EASPercentTimeInMailboxRPC
    • EASPercentTimeInAD
  3. Apply this throttling policy to the iOS 6.1 users who were identified in step 1. Use the Set-ThrottlingPolicyAssociation topic from TechNet online.
  4. Notify users that they may receive the "Cannot Get Mail error that is noted in the "Symptoms" section if they try to act on Calendar items. Note The throttling policy will reduce the effect of the issue on server resources. However, users who receive the error should immediately restart their devices and stop additional processing of Calendar items.
Method 3: Block iOS 6.1 users

You can block iOS 6.1 users by using the Exchange Server 2010 Allow/Block/Quarantine feature. For more information about this feature, see the following Exchange Team blog post:

Also, for updated information about how to use Exchange Management Shell for Allow/Block/Quarantine, see the following Microsoft website:

Microsoft's site has additional information, if needed.