@Frenchie: The best thing to do is to remove the partnership from the device thus stopping the device from attempting to sync at all. Now that is not the best thing for the end user. If possible identify what is wrong with the device (know build issue and upgrade, user workflow education, 3rd party installed on device that is causing the issue). Also in some organizations cannot afford to wait for a user to disable the device so there are ways with reverse proxy server/device (Ex. Threat Management Gateway) to block the User or User-Agent (if known bad device). This will allow the Exchange environment to be functional and give the admin time to work out the issues with the suspect device.