Office 365 ProPlus Deployment and Proxy Server Guidance

DM51673 Thank you for your post.  Starting with Office 365 ProPlus Semi-Annual Channel from July 2019 Version 1902 (Build 11328.20368), several enhancements were added to help address this type of scenario. First, Office has been updated to use API WINHTTP_ACCESS_TYPE_AUTOMATIC_PROXY. This allows us to use system proxy (winhttp) and per-user proxy settings (IE). When using per-user IE proxy, it uses the IE proxy of current user. If the process is running under System (SCCM scenario), it can use the IE proxy for System. Therefore, our first recommendation is to "Configure WinINET Proxy for SYSTEM". In terms of impersonation, if the process is running under System but System account is blocked to access network and doesn't have any proxy settings, our Office Click-to-Run processes attempt impersonation under current logged in user. This also means if no user is logged on, impersonation is not possible which can be common scenario when SCCM deployments occur during off peak hours such as maintenance windows. If you have System proxy configured for WinINET or WinHTTP and are not gaining access to network as expected during Office installs etc., you may want to reach out to Microsoft Customer Service and Support to investigate with you further to scope your specific environmental needs. I hope this explanation helps, thank you for your comments.