I did write this article but it is the best article to write about this common problem.
Cleaning out the folder will solve the issue.
Outlook Secure Temp folder
Unfortunately, this is easier said than done. The subfolder name Outlook creates (on the installation of Outlook) in the Temporary Internet Files folder is quite random.
In Outlook 2003 and previous, the name starts with OLK and is followed by up to 4 random numbers or letters. In Outlook 2007, 2010 and 2013, this folder is called Content. Outlook and then has a subfolder which is named with 8 random numbers and letters.
In addition, by default, you cannot simply browse to the folder to clean it out. Getting to the Temporary Outlook Folder can still be accomplished in 2 easy steps though.
Step 1: Locate the folder
The folder location is stored in the registry in the following key;
Step 2: Get to the folder
- Open the
OutlookSecureTempFolder registry key from the location provided in Step 1.
- Copy the path from the key.
- Open Explorer
- Paste the address in the Address Bar and press Enter
Use OutlookTools or OutlookTempCleaner
Still not easy enough or just don’t want to go in the Registry to find the folder location? I’ve created two free tools which can do the trick as well.
offers besides locating, opening and cleaning up the SecureTempFolder also quite a lot of additional features to troubleshoot and tweak Outlook.
focuses only on dealing with the SecureTempFolder and can also be used in (corporate) login and logoff scripts to clean up the folder without any end-user interaction.
OutlookTempCleaner can detect and empty Outlook’s Secure Temp folder automatically for you.