Only compressing the folders will delete that email permanently from the computer system. That’s great if you deleted an email by accident and want to recover it but bad if an unauthorized third party tries to read your emails.

Microsoft Outlook provides the means to compress a folder immediately but no option to automate the task. It will however display a popup every 100th time that Outlook got closed asking if the user wants to compress the folders.

A far better solution to force Outlook to delete deleted mails completely at every shutdown is to change a setting in the Windows Registry.

Open the Windows Registry by pressing [Windows R], typing [regedit] and hitting [enter]. Navigate to the following Registry key:

HKEY_CURRENT_USER\Software\Microsoft\Office

The next step depends on the version of Microsoft Outlook or Microsoft Office that is installed on the computer. When in doubt perform the operation for all of the following subkeys.

Find the 9.0, 10.0, 11.0 or 12.0 keys in that folder. Click in the Outlook subkey and locate the key PST. If PST is not existing create it. A full Registry path to the right location could look like this:

HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\PST\

Only the 12.0 can change in the path. If you are in the PST key right-click in the right pane and select New > DWord.

Name the Dword PSTNullFreeOnClose. Double-click it afterwards and give it the value 1 to enable it. This ensures that Microsoft Outlook will remove deleted mails completely on every exit from the computer system.

A possible format would be zip for instance. There is however another option for Outlook users. It is possible to add a key to the registry to enable certain file types that are then no longer blocked in Microsoft Outlook. To do so hit Windows R, type in regedit and hit enter.

Navigate to the key HKEY_CURRENT_USER / Software / Microsoft / Office / 10.0 / Outlook / Security for Outlook XP. Change 10.0 with 11.0 if you run Outlook 2003. Right-click in the right window and select New > Key. Name it ‘Level1Remove’ (without the ”) and add one or more file extensions to the key. It could for instance look like ‘.exe;.vbs’.

This would unblock .exe and .vbs file types in Microsoft Outlook.

Advanced Security for Outlook is an add-in for Outlook that gives the user more information about security alerts and options to configure how those alerts should be handled in the future. The default Outlook alert does not mention which program is trying to access Outlook for instance, which can be changed with the help of this program.

Not knowing which program is seen as a threat by Outlook can be a frustrating and sometimes costly experience.

This Outlook add-in is also very useful if you get bombarded with security alerts in regular intervals. You can easily turn them off using this add-in. Whenever a security alert pops up the user has the choice to allow access, block access or call the default handler and check whether he would like to use this action from now on for this security alert.

his add-in for Outlook solves all of the above problems providing the information not only about the type of alert, but also about what program caused it and makes it possible for the user to specify what status this program should have: allow access, block access or run the default Outlook handler. Later on you can change or delete the decision taken.

Advanced Security for Outlook is compatible with all 32-bit versions of Microsoft’s messaging software from Outlook 2000 to the very latest version. The add-in will run on all Microsoft operating systems from Windows 95 on. Downloads are provided at the developer website.