...
- Close Outlook
- Open Windows registry with tool regedit (Help)
- Open the following tree path:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\LowCache\
- Delete the whole key "Extensible Cache" including all subkeys
- Open the Cache folder
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings\5.0\LowCacheCache\ - Delete the whole key "Extensible Cache" including all subkeys here too
- Restart Outlook and check if it is working
...