I am trying to get Office365 OWA to work through our proxy that only allows certain sites. I have added all the IPs from Microsoft in my proxy to communicate with office365. I can log in to: portal.office.com, but when I click on Outlook the page will not display and says http/forbidden. I was wondering is it possible to allow OWA through my proxy with the Microsoft Ips for 365. Word, Excel, opens fine.