I have a GPO that adds safe senders to Outlook 2010. The GPO is configured correctly and I can see that the addresses in the txt file do get added to Outlook. Only... after a few minutes the domains (@domain.com) disappear while the email addresses (email@example.com) remain. This does not affect domains added manually, it only affects domains added via the GPO. Also (as mentioned) the domains do get added (initially I see them in Outlook) but then they magically disappear. Domain is Win2008 R2. Exchange is Office 365 (Exchange 2013). Ideas?