Troubleshooting Email Issues November 02, 2018 18:48 Updated Click the links below for resolutions to common issues. I’m having trouble signing in to Office 365 I see an error message "Your organization could not sign you into this service" When I try to access someone's mailbox folder, I see the error "Unable to open default folders-you do not have permissions to logon" Related articles Open a PST Outlook File Disable Cached Exchange Mode in Outlook