A user complained that Outlook was blocking access to a Word document attachment he sent to a Task using Word's Create Outlook Task command.
I'm receiving this message in Outlook when opening a task created by Microsoft Word:"Outlook blocked access to the following potentially unsafe attachments"I tried the Level1Remove registry fix but this did not work. I disabled Protected View (in Trust Settings) within Word. Still no go. Why is Outlook blocking attachments from its own software (Word)?
This security issue affects Outlook 2007 and up. The file is blocked because it's not a doc file, it's a *shortcut* to the doc file and shortcuts are potentially "dangerous".
You need to configure the security settings to not block the file. In Outlook 2007 and Outlook 2010 you can use the following registry keys to change the Security settings. You'll need to restart Outlook for the keys to take effect.
Enabling ShowLevel1Attach will allow users to open or save potentially dangerous attachments. While an updated antivirus will catch older exploits if users try to save or open the attachment, it could miss new exploits not yet in it's virus definition file.
When you double click on an embedded object, a warning message may be triggered:
Some objects contain viruses that can be harmful to your computer. It is important to be certain that this object is from a trustworthy source.
Do you trust this embedded object?
This dialog is controlled by the AllowInPlaceOLEActivation registry value. Enabling it will allow the embedded object to open without triggering the warning message.
Outlook 2016
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\16.0\Outlook\security DWORD: ShowOLEPackageObj Value: 1 DWORD: AdminSecurityMode Value: 3 DWORD: ShowLevel1Attach Value: 1 DWORD: AllowInPlaceOLEActivation Value: 1
Outlook 2013
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\15.0\Outlook\security DWORD: ShowOLEPackageObj Value: 1 DWORD: AdminSecurityMode Value: 3 DWORD: ShowLevel1Attach Value: 1 DWORD: AllowInPlaceOLEActivation Value: 1
Outlook 2010
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\14.0\Outlook\security DWORD: ShowOLEPackageObj Value: 1 DWORD: AdminSecurityMode Value: 3 DWORD: ShowLevel1Attach Value: 1 DWORD: AllowInPlaceOLEActivation Value: 1
Outlook 2007
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\12.0\Outlook\security DWORD: ShowOLEPackageObj Value: 1 DWORD: AdminSecurityMode Value: 3 DWORD: ShowLevel1Attach Value: 1 DWORD: AllowInPlaceOLEActivation Value: 1
Do It For Me
I have a reg file to unblock all attachments and OLE objects (containing the values above). Download and run the .reg file for your version of Outlook.
Network users may be blocked by group policy, so this should only be used by SOHO users - everyone else should speak to their admin.
ShowLevel1Attach 2016 ShowLevel1Attach 2013
ShowLevel1Attach 2010 ShowLevel1Attach 2007
You'll need to restart Outlook for the key to take effect.
More Information
Information for administrators about e-mail security settings in Outlook 2007
You cannot open linked file attachments in Outlook: "Outlook blocked access to the following potentially unsafe attachments"
Joy says
Worked perfectly. Thanks!
Richard says
Great work, as usual! Thanks.
Philip says
Figured it out; for some reason if you put the .display it keeps the attachemnt; how bizare :-)
Diane Poremsky says
Definitely odd, it must be something with the "hidden" message. I'll have to test it.
FWIW, i think the message was probably telling you the attachment might not be visible to the recipient but it would still be attached.
Philip says
Hello, Firstly thanks for your site - its great.
I've been able to create a task from an email and add an attachement (which shows up in outlook.com) however,
you get the security outlook has blocked on the client. I know Clearcontext can create a task with an email so it may possible not be
a registry setting that prevents creates the security warning as when I use clearcontext it works fine.
Any ideas "-)
Diane Poremsky says
the message sounds like you are using a version of outlook with the june 13 2017 update - it causes that message (intentionally!) under a few circumstances.