Mar 062007

Today I updated my Outlook Unsafe Attachment Unlocker utility. For some reason I noticed the select-all checkmark did not toggle. It only did a Select-All, but not an Unselect-All. Now it does. And the context-menu now points to the correct address of this weblog. Get it here.

Click to enlarge

When I get my hands on an Office 2007, I’ll see whether the utility can be made Office 2007 compatible.

Apr 122005

I still get a lot of search hits from people looking for a way to change the extensions that cannot be viewed in Outlook, because Microsoft decided in all her wisdom to mark a lot of extensions as “unsafe”. In Outlook Express there is a nice dialog to change this behaviour, in Outlook there is not. You can do it by editing the registry by hand, but a lot of people are afraid to do so.

For that reason, I created ouau.exe, or “Outlook Unsafe Attachments Unblocker”. It detects your Office version (which you can override) and lists the extension so you can block/unblock them. There’s a handy “select all” radiobutton that will save you some clicking.

Here is a screenshot.

Click here to download the program. It’s in WinRAR format, so you need to extract it first.

Apr 202004

OUAU should now work for all Office versions, and you can select the Office version (if for some reason you have partial Office installations) and it will reread and write the appropriate registry-entry.


  • Ability to change Office version by using the radiobuttons
  • Added link to this blog in context-menu

To do

  • Close the application when unsupported Office version is detected (detection and errormessage is already in place)
Apr 202004

I tried ouau here at work, and we’re using Office 2002/XP. It finds the correct Office version, I’m able to make changes to the blocked extensions, which I can verify by restarting the program: it finds the new settings. But the new registry-setting resort no effect: right-click and send-to-mail-recipient of a unblocked extension (e.g. .EXE) still results in Outlook saying that the attachments are potentially unsafe. What’s going on here? Something to do with (group)policies?

Update: I think I already know: Exchange administrators can add/remove Level 1 and/or Level 2 extensions within the Exchange-server settings. This can not be overruled by the Outlookclient. So, I guess I’ll have to find another way to test other Office versions.

Apr 182004

Another update to OUAU, now version


  • Detection of Office 2000
  • Detection of Office 2002/XP
  • Detection of Office 2003

To do:

  • When user selects an Office version other than detected, modify the correct registry-entries, instead of detected version
  • Close the application when unsupported Office version is detected (detection and errormessage is already in place)
Apr 182004

Minor update to ouau, bringing it to version


  • All extensions show a description as tooltip when hovering the extension
  • When “Select all” is checked and an extension is unchecked, “Select all” will be unchecked as well
  • New Icon
Apr 162004

Tim heeft ouau getest, en zegt dat het niet werkt. Hij heeft Office 2002 (XP). In TweakXP is wel te zien dat alle extensies zijn vrijgegeven. Klopt helemaal Tim, ouau werkt op dit moment alleen maar met Office 2003 (interne versie 11.0). Ik zal zo snel mogelijk zorgen dat alle Office versies vanaf 2000 werken.

Apr 152004

Zojuist even een Outlook Unsafe Attachments Unblocker gemaakt. Dat gezeur van Outlook dat ‘ie sommige files unsafe vindt om te versturen. Dat maak ik zelf nog wel uit.
Klik hier om te downloaden.