On a computer that has Microsoft Office Outlook 2003
installed, external content is always blocked for attached e-mail messages
after you install security update 949031 (security bulletin
This section, method, or task contains steps that tell you how to
modify the registry. However, serious problems might occur if you modify the
registry incorrectly. Therefore, make sure that you follow these steps
carefully. For added protection, back up the registry before you modify it.
Then, you can restore the registry if a problem occurs. For more information
about how to back up and restore the registry, click the following article
number to view the article in the Microsoft Knowledge Base:
How to back up and restore the registry in Windows
To resolve this problem, apply hotfix
package 959628, and then configure the DisableSenderTypeSecurity registry entry
to enable the hotfix package. To do this, follow these steps:
- Apply hotfix package 959628.
information, click the following article number to view the article in the
Microsoft Knowledge Base:
Description of the Outlook 2003 hotfix package (Outlook.msp): December 16, 2008
- Configure the DisableSenderTypeSecurity registry entry. To
do this, follow these steps:
- Click Start, click
Run, type regedit, and then click
- Locate and then click the following registry subkey:
- On the Edit menu, point to
New, and then click DWORD Value.
- Type DisableSenderTypeSecurity ,
and then press ENTER.
- Right-click DisableSenderTypeSecurity
, and then click Modify.
- In the Value data box, type
1, and then click OK.
- Exit Registry Editor.
If the original sender of the attached e-mail message that has
the blocked content is not someone from your own Exchange organization, the
images may still be blocked. In this scenario, you have to add the domain name
of the sender if you want Outlook to automatically display the images in the
attached e-mail message.
For most external content, Outlook checks the sender type of
the e-mail messages as part of the test for whether to show the contact. E-mail
messages from an internal sender are considered safe. Therefore, external
content is allowed. Security update 949031 changed this behavior for attached
e-mail messages and file system based e-mail
messages. With that update applied, the external content is blocked regardless
of the sender type. This hotfix, together with the registry value, adds the
sender test back. Therefore, if the e-mail message is from an internal sender,
the external content is downloaded successfully. The new registry value
actually disables the bypassing of the sender type. Therefore, the name of the
registry entry is somewhat misleading. By setting the value, you tell Outlook to include the sender type in the test for safety for these
kinds of messages.
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.