Meeting requests that are sent to resource mailboxes are not always forwarded automatically to delegates in Outlook in Office 365

Applies to: Microsoft Outlook 2010Microsoft Office Outlook 2007Exchange Online


In a Microsoft Office 365 environment, meeting requests that are sent to resource mailboxes (for example, to conference room or equipment mailboxes) are not always forwarded automatically to the associated delegates in Microsoft Outlook.


This issue occurs if there are externally linked images in the AutoSignature of the person who sent the meeting request. These externally linked images may stop the automated forwarding process.


To resolve this issue, use one of the following methods, as appropriate for the situation.

Method 1

Remove the externally linked images from the AutoSignature.

Method 2

To have us fix the problem for you, go to the "Fix it for me" section. If you prefer to fix this problem yourself, go to the "Let me fix it myself" section.

Fix it for me

To automatically add and set up a BlockHTTPImages registry entry to prevent the Outlook client from displaying externally linked images, click the Fix it button or link. Then click Run in the File Download dialog box, and follow the steps in the Fix it wizard.

  • This wizard may be in English only. However, the automatic fix also works for other language versions of Windows.
  • If you are not on the computer that has the problem, save the Fix it solution to a flash drive or a CD, and then run it on the computer that has the problem.
Then, go to the "Did this fix the problem?" section.

Let me fix it myself

Important 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:
322756 How to back up and restore the registry in Windows
Add and set up a BlockHTTPImages registry entry to prevent the Outlook client from displaying externally linked images. To do this, follow these steps:
  1. Exit the Outlook client.
  2. If you are running Windows 7 or Windows Vista, click the Start button, type regedit in the search box, and then press Enter.
    If you are running Windows XP, click Start, click Run, type regedit in the Open box, and then click OK.
  3. Locate and then click one of the following registry subkeys, depending on the version of your Outlook client.
    Outlook 2007
    Outlook 2010
  4. On the Edit menu, point to New, and then click DWORD Value.
  5. Type the following name for the new value, and then press Enter:
  6. Double-click the new BlockHTTPImages value.
  7. In the Value data field, type 1, and then click OK.
  8. Exit Registry Editor.
  9. Restart your computer.
Note When you enable the BlockHTTPImages registry entry, Office may block more than just linked HTTP images.

Did this fix the problem?
  • Check whether the problem is fixed.
  • We would appreciate your feedback. To provide feedback or to report any issues with this solution, please leave a comment on the "Fix it for me" blog or send us an email message.


To implement the registry change through the Group Policy feature, use the following registry subkeys.
Outlook 2007
For more information about Group Policy, go to the following Microsoft TechNet website:
Still need help? Go to Microsoft Community.