Installation instructions You can install McAfee Security for Microsoft Exchange 8.6.3 " instead of" or "over" MSME 8.6.1 with HF1218399, HF1236399, or MSME 8.6.2. This release is based on the Windows Installer patch framework. You must install these components for the product to work flawlessly: The software (either the standalone installation or deployment through McAfee ePO server) on McAfee Security for Microsoft Exchange system. The policy extension on the McAfee ePO server (version: 22.214.171.124). Note: Uninstallation of this update is not supported. To remove this update and revert to the original setup, you must reinstall the McAfee Security for Microsoft Exchange 8.6.1 software. For information about installing or upgrading McAfee Security for Microsoft Exchange, see McAfee Security for Microsoft Exchange 8.6.0 Installation Guide. Files included with this releaseInstall the patch on standalone systems Install the patch on standalone servers. Install the patch using McAfee ePO Install the patch on managed servers using McAfee ePO. Install the policy extension Install the policy extensions on the McAfee ePO server. Test the installation You can verify if the patch is applied correctly by verifying the version of these files in the respective exchange roles.