When the Microsoft Dynamics CRM 4.0 E-mail Router service calls a method in the GetDecryptionKey API, the key is not encrypted.

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:
This problem is fixed in the latest cumulative update rollup for Microsoft Dynamics CRM 4.0.

After you install this hotfix, you must add the subkey to the registry that is located on the computer that is running the Microsoft Dynamics CRM 4.0 client and on the Microsoft Dynamics CRM 4.0 server. To do this, follow these steps:

• Add the
  SecureCredentialFlow
  subkey to the registry on the computer that is running the Microsoft Dynamics CRM 4.0 client. To do this, follow these steps:
  1. In the Microsoft Dynamics CRM 4.0 client, click Start, click Run, type regedit, and then click OK.
  2. Locate and then click the following registry key:
     HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM
  3. On the Edit menu, click New, and then click DWORD Value.
  4. Set the name of the subkey to SecureCredentialFlow.
  5. Right-click the SecureCredentialFlow subkey, and then click Modify.
  6. In the Value data box, type 0 in the Value data field, and then click OK.
  7. On the File menu, click Exit.
• Add the
  SecureCredentialFlow
  subkey to the registry on the computer that is running the Microsoft Dynamics CRM 4.0 server. To do this, follow these steps:
  1. In the Microsoft Dynamics CRM 4.0 server, click Start, click Run, type regedit, and then click OK.
  2. Locate and then click the following registry key:
     HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSCRM
  3. On the Edit menu, click New, and then click DWORD Value.
  4. Set the name of the subkey to SecureCredentialFlow.
  5. Right-click the SecureCredentialFlow subkey, and then click Modify.
  6. In the Value data box, type 0 in the Value data field, and then click OK.
  7. On the File menu, click Exit.

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.