Symptoms: When you open an email in a new window, start a reply in a new window, or perform any other tasks that open a secondary Window in Outlook 2013, you only see the border of the new window for several seconds.
Workaround: You can maximize the window once it appears, then close it to make the window open full screen from that point on. This will prevent the bug from appearing since it only happens with windows that are not full screen.
Resolution: This is a known bug when using Outlook 2013 remotely on a Windows 7 computer. Microsoft has released a hotfix for this bug. To resolve this issue, download and install the hotfix using the link below.
LINK: Hotfix Download
Once downloaded, open the Zip file and run the version of the hotfix for your version of Windows 7 (32 or 64 bit). If you don't know what version of Windows you have, try both files. Only the correct file will work. Once the hotfix is installed, reboot your computer.
NOTE: You must close all open hosted applications before installing the hotfix.